As fun as it is to play a morally grey character serving a dark patron or have a good-aligned character struggling with an evil source of power, I sometimes enjoy playing a good-aligned warlock that isn't at odds with their patron. This is easy to make work with a Celestial or Archfey warlock, but with the other patrons available, it's not as obvious. Here I've come up with 6 warlock patrons—two fiends, two great old ones, and two hexblades—that a good aligned character could easily get along with.
A devil who cooperates with organized religion in order to harvest souls from sinners and heretics.
Alignment: Lawful Evil
History: Like most high-ranking devils, Uzriath wants nothing more than to gather souls and use them to expand her army of fiends. Unlike most devils, she has realized that the easiest and most reliable way to do this is not by corrupting mortals or doing evil deeds, it's by teaming up with organized religion. Uzriath has partnered with some major church, agreeing to act as a boogeyman that keeps believers in line in exchange for the souls of all the sinners and heretics that the church punishes. Not only does she get a steady supply of souls fresh off of the blades of paladins, but it also keeps the godly types who usually get in the way of devils off of her back.
Although Uzriath is as evil as any other devil while in The Nine Hells, she has a solid understanding of the tenets of goodness and follows them when dealing with mortals on the material plane. She has a reputation to keep up with the church, after all. Evil acts by either her or her warlocks put the entire arrangement in jeopardy, so she encourages her warlocks to perform good deeds and follow the expectation of the religion she has partnered with.
When Uzriath chooses a warlock, they are almost always a lawful good individual who is loyal to the religion she has partnered with. Sometimes they will also be paladins or clerics in addition to a warlock. She prefers warlocks who are willing to go out and slay evildoers themselves, rather than sit back at a temple and let regular holy warriors do all the work.
Personality: Uzriath is polite, eloquent, and relatively reserved. She knows that her followers are going to listen to the gods first and her second, and doesn't try to fight that. She frequently reminds her warlocks to stay on the path of righteousness and will swiftly and harshly correct them if they falter. Her evil nature only comes out in the heat of battle, when the warlock has a perfect opportunity to execute some heretic; Uzriath will always goad them into slaying the target and argue against mercy, unless it seems like the person might not deserve it and their death could harm her standing with the church.
A rare good-aligned demon who is trying to prove his good nature to an unwelcoming world.
Alignment: Neutral Good
(Edit: When I made Mirgan, I didn't realize that Balors had to go perform numerous evil deeds to reach that status, I incorrectly assumed that they were born as Balors. I only picked Balors because it was the weakest demon I could find that was capable of being a warlock patron. Feel free to switch out what sort of demon he is based on what makes sense in your setting, or come up with some reason why he would be pressured into performing those evil deeds and rising in the ranks.)
History: Mirgan is a Balor from the abyss, although you couldn't tell from his demeanor. He always knew that there was something off about himself compared to the other demons. He was unbothered by not being the most powerful Balor in the land, he didn't take much pleasure in the torture of others, and he enjoyed moments of silence and peace far too much. He served as a commander under a demon lord for much of his early life, up until the point when he rose to the material plane to sew chaos there with his army. He was immediately enamored with the world above, with it's beauty and the peaceful lifestyles the natives lived, which lead him to defect.
Mirgan carved out a place for himself deep in the wilderness, hoping to live there forever, but hordes of vengeful demons and holy paladins alike drove him back into the Abyss. He refused to serve the demon lords again, for he had realized that he was not fundamentally tied to evil like they were. More than anything else, he wanted to be good. However, the paladins he had met on the surface made it clear that he was not welcome because of what he was. The gods and other forces of good hated demons. He could never be accepted for who he is inside.
With no other hope of convincing the good-aligned gods to give him a chance, Mirgan turned to righteous mortals to intercede for him. He promises to give these mortal a piece of his power, the only thing of value he holds, in exchange for them to vouch for him to the gods. He asks that his warlocks use his powers for good causes that will earn him the gods' favor.
Despite his commitment to good, Mirgan is often forced to commit terrible acts of violence in order to keep himself alive in the Abyss, and often does things he doesn't understand are immoral because of where he was raised. He frequently berates himself for his mistakes, and each one only makes him more motivated to achieve goodness.
Personality: Mirgan has a good heart, unlike every other demon, and is obsessed with proving that. He hands out compliments freely and makes a point to be kind and supportive to his warlocks. He is hyper-critical of his own behavior and prone to beating himself up whenever either he or one of his warlocks does something evil. While his heart is in the right place, being raised in the Abyss leaves him clueless about some of the finer points of morality, like the fact that it's probably overkill to attack someone if they look at you wrong. He trusts his warlocks to correct and guide him in that respect.
Great Old Ones
An eldritch horror who just wants to be liked.
While the deeper mechanisms of an eldritch horror's mind is inscrutable, one can typically deduce some kind of motivation from them by watching their behavior. They seem to be capable of having goals (or at least the ones who bother to make pacts with warlocks are), although why they would ever need to accomplish these goals is often a mystery.
Vredi is a perfect example of this phenomena. As far as anyone can tell, all Vredi cares about is having a positive public perception among the mortal beings of the material plane. It does not seek direct praise, attention, or affection from mortals, and instead only wants people to have a generally positive reaction to hearing Vredi mentioned. Considering this, it's odd that Vredi is so open and honest about being a horrific eldritch monstrosity. Its warlocks have suggested that it sees its reputation as a game and being an eldritch horror increases the challenge, but even they are unsure of that.
Vredi has a large number of warlocks and actively recruits individuals who seem naturally generous and friendly. It directs them to do charity work in the name of Vredi, and in return grants them magical power. Pacts with Vredi require warlocks to keep up a positive reputation and not perform evil acts, at least publicly, and any warlock that starts to reflect poorly on Vredi will have their powers revoked. If the warlock performs an evil act but is never caught, Vredi will not care about that whatsoever.
Vredi also cares about being liked by its warlocks, and therefore treats them with understanding and respect most of the time. Warlocks of Vredi often hear soft whispers coming from just over their shoulder as they go throughout their day; while the sound is frightening at first, if they listen closely, they will hear that the voice is Vredi is giving them words of encouragement in Deep Speech.
Personality: Being an inscrutible eldrtich monstrosity, a personality for Vredi is hard to pin down. It goes about being liked in an strategic and almost clinical way; there is rarely any warmth or real feeling in the messages it sends to its warlocks.
An elder god who knows all there is to know, but misses the excitement of learning, so it experiences it vicariously through warlocks
History: Lagoggth, the great devourer of knowledge, is said to have existed for as long as there have been things to know. Some ancient texts claim that Lagoggth has consumed every truth in the world, and that no fact can be real until Lagoggth has digested the infinite complexities of information and excreted it as simplified fact that mortals can comprehend. It is omniscience given consciousness.
Lagoggth still hungers for knowledge, although there is none left that it has not already consumed. For this reason it seeks out mortals, who by their nature know almost nothing and learn new things every day. When Lagoggth makes a pact with a mortal, it means the mortal is allowing it to sit within their minds at all times, vicariously experiencing the rush that comes from learning something new. Lagoggth only offers to make pacts with those who have a thirst for knowledge and a deep appreciation for the fun of learning.
Lagoggth resists the urge to tell their warlocks any information directly, especially large and exciting facts that could have a great emotional impact, because the vicarious experience is better when the warlock learns things on their own. However, it will send its warlocks on quests to uncover hidden lore and ancient secrets. If there is a specific piece of knowledge that the warlock particularly wants to uncover, Lagoggth will be thrilled to steer them in that direction, but will not necessarily let it be easy.
For all of its insistence on letting its warlocks learn on their own and fight hard for knowledge, Lagoggth sometimes can't help themselves when it comes to handing them tiny bits of truth. Little sub-par bumps of curiosity can hold Lagoggth over until the next big rush of revelation. Warlocks of Lagoggth will often hear bits of useless trivia whispered to them in their dreams.
Personality: Lagoggth has a one track mind as far as anyone can tell, and is completely obsessed with information and learning. They aren't the type to hold actual conversations with their warlocks, so their demeanor is unknown.
A sentient battleaxe who resents the sly lich who created him, and yearns to be wielded by an aggressive, honorable warrior.
Alignment: Chaotic Neutral
History: Spaltier began as an ordinary battleaxe, but was given sentience and magical power by an evil wizard named Tsidox. Spaltier craved nothing more than victory, and was enchanted in such a way that a wizard attuned to it could wield him with as much skill and force as the fiercest barbarian. In a scheme taking several years and with the help of Spaltier, Tsidox took control of a rather large kingdom, and drained that kingdom's treasury in order to build a phylactery and achieve lichdom.
Once Tsidox was a lich, he didn't feel the need to use Spaltier anymore. The magical axe was locked away in a storage room in the basement of the castle for over a hundred years. Spaltier dreamed of the day when he would once again be called to arms, but eventually lost hope, and grew to despise Tsidox for discarding him.
Finally, the day came that Spaltier would be released—but not by Tsidox. Instead it was an insurgent from the oppressed kingdom who had snuck into the castle in search of Tsidox's phylactery. The rebel took Spaltier with him, and that alone was enough to convince the battleaxe to betray the lich and swear loyalty to the rebels. Spaltier knew exactly where the phylactery was and how to destroy it. His help allowed the rebels to break through Tsidox's forces, smash the phylactery, and kill Tsidox, freeing the kingdom.
Spaltier had never felt so accomplished, and the way he was hailed throughout the kingdom as a great, victorious hero made him even happier. The citizens of the kingdom weren't sure how to reward a sentient battleaxe, so they asked him what he wanted in return for his service. He asked that he could continue being a great hero, as he'd never had so much fun in his life. He was passed off to a traveling adventurer who had stopped to help overthrow Tsidox, and the two fought side by side for years.
After that adventurer died, Spaltier was passed to another adventurer, then another, and so on and so forth for hundreds of years. He will only allow himself to be wielded by fierce warrior with a true lust for battle, glory, and heroism. He hates serving evil masters because they remind him too much of Tsidox; for the same reason, he loves to cleave evildoers in two, especially undead ones.
Personality: Spaltier is fiery and aggressive, but not such a slave to bloodlust that he promotes the killing of innocent people. He will goad his wielder into any fight that seems like it could be for a good cause. It's hard to say whether or not he is truly good-aligned, but the only thing he loves more than fighting is basking in glory and praise after a righteous victory, and that's enough to keep him on the path of goodness.
The Dusk Blade
A sentient sword who has grown attached to the peasant family who stole it from its evil master long ago.
Alignment: Neutral Good
History: Once, countless years ago, an evil conquerer in league with demons wielded a notorious sword known as the Dusk Blade. It was said that when that conquerer pointed the sword at any person or place, it's marked the "dusk" of that target's existence, and they were doomed to perish. For decades the conquerer terrorized the world, and each year more and more innocent people were crushed underfoot and enslaved.
However, one woman fought back, a legendary folk hero named Gwerina, most often known as Gwerina the Liberator. She disguised herself as a guard to reach the conquerer's side, then ambushed him, stole the Dusk Blade, and killed him with it. Fearing that she would be captured and killed by the conquerer's loyal subordinates, Gwerina fled with the Dusk Blade to the countryside, where she hid on a secluded farm for the rest of her life.
She quickly learned the the Dusk Blade held a magical sentience within it. Gwerina was lonely and only had the blade for company, so she mounted it on the wall beside the dinner table and chatted with it at the end of every day. At first, the Dusk Blade was furious about being taken hostage and constantly demanded to be returned to its rightful owner.
As they spoke with one another, Gwerina learned that the blade had suffered through relentless brainwashing and manipulation by the conquerer, and would be plunged into the painful fire of a forge whenever it spoke out against it's master. The Dusk Blade came to realize that it no longer was at risk of being subjected to such torture, now that its original master was dead and its new owner was far kinder.
The Dusk Blade grew to enjoy life on the farm. It passed the time by enchanting every piece of farm equipment, making self-sharpening knives and hoes that tilled the land on their own. Gwerina's little farm was quite productive with the Dusk Blade's help, to the point where she began going into town to sell her excess crops. There she met a charming man who became her future husband. The two had many children together, the start of a long, happy family line.
Gwerina has long since passed away, but her descendants live on, passing the Dusk Blade down from generation to generation. It prefers to live a peaceful and modest life, but if the family it holds so dear is put in danger, it will not hesitate to take to the battlefield again. It is a bit out of practice, but with enough time and training it may return to its former glory as the most feared weapon in the world.
Personality: The Dusk Blade has the demeanor of a wise old man—calm, thoughtful, and patient. It greatly prefers peace to violence, and will try to talk its wielder out of hacking and slashing through their problems. It is very concerned for the safety of anyone it considers family.