Friends and Allies
Like virtually all Jedi, Obi-Wan deeply respected Yoda and was trained by him as a young boy; prior to Obi-Wan becoming Qui-Gon Jinn's apprentice. He obeyed Yoda usually without question.
After Obi-Wan died, he entrusted Luke's training to Yoda.
Like most Jedi, Obi-Wan held Mace in high esteem for his mastery of Form VII. Mace also held Obi-Wan in high esteem for his mastery of Form III. However, despite their mutual respect for each other, Obi-Wan often disagreed with Mace's somewhat questionable decisions. This was due to the fact Obi-Wan was a moderate who followed the Jedi Code and Mace was an extremist with a secret emotional attachment to the Galactic Republic.
Obi-Wan held his mentor Qui-Gon in high esteem. However, they often clashed due to philosophical differences; Obi-Wan was more willing to obey the Jedi High Council and the follow Jedi Code, while Qui-Gon was more willing to defy both of the two latters. When Darth Maul killed Qui-Gon, Obi-Wan was devastated and vowed to pick up where his mentor left off.
After Anakin turned to the Dark side and became Darth Vader, Qui-Gon's spirit taught Obi-Wan the technique of retaining his identity through the Force (something Qui-Gon had himself learned from the Force Priestesses), a technique that enabled him to become a Force Ghost after death.
Obi-Wan first met Padmé shortly after the Invasion of Naboo started, when he and his mentor Qui-Gon rescued her from the Trade Federation's battle droids. They did not have much interaction with each other. However, throughout the Clone Wars, the two became close friends.
In Revenge of the Sith, their friendship became strained after Anakin told her of Obi-Wan's apparent intent to use him as a spy for his own purposes. Padme did not believe Obi-Wan when he told her of husband's dark deeds, mainly because she was in denial and partly because of what Anakin told her. To reassure herself that what he had said was not true, she traveled to Mustafar to ask Anakin herself; unknown to Padmé, Obi-Wan had stowed away on her Naboo star skiff, so he could find Vader and confront him.
Before her death, Padmé told Obi-Wan that there is still good left in Anakin and one day he can be redeemed. However, though Obi-Wan was just as heartbroken as she was about Anakin's transformation, he could not bring himself to believe her.
Obi-Wan first met Ahsoka during the Battle of Christophis. At first, Obi-Wan thought Ahsoka was going to be his apprentice until Ahsoka revealed that she was assigned to be Anakin's apprentice. Later, Obi-Wan told Anakin off for being so harsh with her and told him to cut her some slack. Over the years, Obi-Wan's trust in her grew.
When Ahsoka was accused of treason, Obi-Wan was one of the extreme few that were doubtful she had committed the crimes. When Tarkin demanded that Ahsoka be expelled from the Jedi Order and turned over to the Republic military courts, Obi-Wan tried to convince the members of the Jedi High Council to refuse and stand by Ahsoka due to seeing that there was no real proof of her so-called treason. Unfortunately, Obi-Wan was out-voted by the other Council members, and Ahsoka was cast out of the Jedi Order. Although Obi-Wan didn't agree with the Council's decision, he did nothing to help clear Ahsoka's name. When Barriss Offee was exposed as the true culprit, Obi-Wan didn't seem surprised that Ahsoka was innocent and was saddened when she left the Jedi Order for good.
Hondo held Obi-Wan, along with Anakin and Dooku hostage. But after they freed themselves, they left Hondo's base with no intention for revenge, which Hondo respected. Three years later after Darth Maul returned, Hondo helped Obi-Wan fight Maul and his brother Savage Opress. Hondo seemed to respect Obi-Wan greatly.
After Luke was born, Obi-Wan took him to Tatooine, to be raised by his father's step-brother Owen Lars, and his wife Beru Whitesun, in order to protect him from Palpatine. Obi-Wan watched over him for nineteen years. Before discovering Obi Wan's true identity, Luke believing him to be a strange hermit, under the name of "Ben Kenobi".
Upon the arrival of R2-D2 and C-3PO, Luke learned of Obi-Wan's former identity and life as a Jedi. After this knowledge, he gained great respect and admiration for the Jedi Master. During their journey to Alderaan, the two quickly became good friends. On the first Death Star, Obi-Wan was killed by Darth Vader while attempting to escape. Luke was devastated by the death of his mentor, but continued to fight in in the Galactic Civil War, so that Obi-Wan's death would not be in vain.
When he discovered that Vader was his father, Luke became angry that Obi-Wan had lied to him, but eventually forgave him.
Obi-Wan and Maul had been enemies since the Invasion of Naboo. When Maul killed Qui-Gon, Obi-Wan picked up when he left off and defeated him. Unknown to Obi-Wan, Maul survived the injuries Obi-Wan had inflicted and after several attempts to obtain revenge against the Jedi master decades later eventually killed Kenobi's love interest, Satine Kryze, to cause him pain.
Obi-Wan initially respected Dooku for training his beloved mentor Qui-Gon. This came to an end after seeing with his own eyes that he had become a Sith Lord. He later learned from the Pikes Syndicate that he was the man called Tyranus that Jango Fett told him about and realized that his Sith name is Darth Tyranus.
Unlike most people such as Anakin, Obi-Wan was unimpressed with Palpatine and was the first person who saw what he really was due to seeing him as another politician. When Dooku revealed to him the existence of Darth Sidious and that the Dark Lord of the Sith had hundreds of Senators under his control, Obi-Wan didn't believe a word of it, stating the Jedi High Council would've sensed it. However, as the Clone War dragged on, Obi-Wan began to realize that Dooku was telling the truth.
After the Invasion of Coruscant, Mace Windu revealed that Darth Sidious was traced to 500 Republica, the residence of the officials of the Republic Government. Obi-Wan realized that Dooku was indeed telling the truth and later warned Anakin to be careful around Palpatine. After the Execution of Order 66 and the Declaration of a New Order, Obi-Wan learned that the now Emperor Palpatine and Darth Sidious were one and the same. Obi-Wan would live the rest of his life with the horror that the Jedi Order had been too blind to stop Palpatine before it was too late.
When Obi-Wan first met Anakin, Obi-Wan apparently didn't think much of him due to how young he was despite having seen how high his midi-chlorian count was. Whereas most members of the Jedi High Council were against Anakin's training due to his age, Obi-Wan's reason for opposing it was because he was secretly jealous of him. After Qui-Gon was killed, he took Anakin in as his apprentice to fulfill his mentor's dying wish. He often clashed with Anakin for his frequent disobedience, as well as his impulsive and prideful attitude. However, Obi-Wan secretly always defended Anakin at every turn and always found a way to make Anakin's mistakes his own. He was also the first to insist that Anakin be made a Jedi Knight.
When Anakin turned to the Dark side and became Darth Vader, Obi-Wan was heartbroken and only resolved to fight Vader because Yoda ordered him to do it. During their duel, Obi-Wan kept trying to talk some sense into his former apprentice, but as Vader coldly rebuffed all his pleas and made vicious attempts to murder his former mentor, he eventually accepted that the boy he had trained was gone. After Obi-Wan dismembered Vader and won the duel, he could not bring himself to murder his defenseless enemy in cold blood and remorsefully left Vader for dead.
He later took Luke to Tatooine to keep him safe and later learned during a Holonet broadcast of the Subjugation of Kashyyyk that Vader was still alive and had been rebuilt as a cyborg; Obi-Wan was shocked and horrified, partly because Vader was still alive, but mainly because of what his actions had resulted in his former friend becoming, due to Obi-Wan not killing him when he had the chance to put Vader out of his misery.
Nineteen years later, Obi-Wan told Luke that Vader betrayed and murdered Anakin, which was true from a certain point of view. Not long afterwards, Obi-Wan re-encountered Vader once more on board the first Death Star. Vader engaged his former mentor in a final lightsaber duel, expressing contempt for him due to his advanced age. When Obi-Wan left himself wide open, Vader cut him down without mercy or remorse.
Obi-Wan continue to believe that Vader was irredeemable and there was no good left in him, even as a Force spirit. However, this was disproved when Vader's son, Luke, was being tortured by Palpatine, and Vader broke away from the Dark side of the Force, becoming the good person he once was; proving that he was a lousy friend to Anakin in the end.
Obi-Wan and Tarkin work together very well during the Clone Wars. However, unlike Anakin Skywalker, Tarkin appeared to have virtually no respect for Obi-Wan.
Despite the fact he fought alongside Obi-Wan in the Clone Wars, Tarkin arrogantly underestimated his former ally, believing the latter was killed in the Jedi Purge.