The Olympic champ turned reality star spoke to 20/20's Diane Sawyer in an interview that aired Friday, discussing everything from the first time he felt different to his three marriages and what's next in his journey.
Here are some of his most riveting revelations:
1. He's Still Attracted to Women But Says He's 'Asexual' for Now"No, I'm not gay. I am as far as I know, heterosexual," he told Sawyer. "I've never been with a guy, I've always been married, raising kids."
But when pressed later about romance, Jenner used another term.
"Let's go with asexual," he said. "For now. Yeah, I'm gonna learn a lot in the next year."
2. Kris Knew He Cross-DressedBecause Jenner began taking hormones in the 80s, he estimated that he had a 36B breast size. And he said he told now ex-wife Kris Jenner about his habit of wearing women's clothes at home.
"I downplayed it," he said. "I feel in a lot of ways when you love someone you don’t want to hurt them."
As for their sex? Jenner said he thought it was "pretty good."
"I loved Kris. I had a wonderful life with her. I learned a lot from her," he said.
3. He's Still a Republican – and Religious"I'm kind of on more of the conservative side," he told an astonished Sawyer.
But he plans to use his story to spread awareness and acceptance.
"I had this feeling, kind of a revelation, that maybe this is my cause in life," he said. "This is why God put me on this earth ... to deal with this issue."
4. He Contemplated SuicideAfter cameras caught him going into the doctor's office for a tracheal shave last year, he feared his secret would come out before he was ready – and thought about killing himself.
"That night, I thought, 'It's over.' I was in this walking up and down this hall back and forth all night long. Heart pounding," he told Sawyer. "I thought, 'Wouldn't the easiest thing to do right now is go in the other room, get a gun. Pain is over. Done. Go to a better place.'
"I thought, 'I can't do something like that. I want to know how this story ends.' "
5. He's Picked a New Name and Is Considering Sex Reassignment SurgeryJenner wouldn't tell Sawyer what his new name will be ("The media would go crazy"), but he did say he's been on hormones and is thinking about further physical changes down the line.
"Those are all things that are out there in the future for me to explore," he said. "I would do it so quietly, no one in the world would ever know."
6. How the Kardashians ReactedThough Khloé Kardashian had a "tougher time," Jenner said Kim Kardashian West has been the "most accepting" – along with husband Kanye West.
In fact, Kardashian West caught him in women's clothing – something that started when he was 8 or 9 and would sneak out in his sister's dress – in their home but stayed silent for years.
Now, she's ready to help Jenner explore his identity as a woman, telling him, "You gotta look good."