Hilton, whose real name is Mario Armando Lavandeira, told ABCNews.com that, although his encounter with Aniston did not prompt him to be "more positive," her stamp of approval means a lot to him.
"It's really rewarding and inspiring and heartwarming to have Jennifer Aniston give me her seal of approval," said Hilton, who will turn 33 next month. "And for her to have made this proclamation on Ellen DeGeneres' show means I'm turning the corner in terms of public perception. There's no turning back."
Before Aniston and DeGeneres turned to the serious topic of her encounter with Hilton, they had some fun with an early birthday present DeGeneres gave to Aniston, who turns 42 next week. On Thursday's "Ellen DeGeneres Show," DeGeneres presented Aniston with a pair of vibrating nipple ads, and the good-natured actress put them on under her blouse.
As DeGeneres turned on the device, Aniston yelped, "Am I getting milked?"
"What's happening?" Aniston said, laughing out loud.
"Isn't that lovely?" replied DeGeneres, who also had on a pair. "It will enhance you."
"I don't want to be enhanced," Aniston responded, to which DeGeneres said, "Yes, you do."
Later, DeGeneres asked Aniston about her chance meeting with Hilton at a Los Angeles parking garage last August.
It was, Aniston said, "one of those moments you just never expect to happen. I had finished dinner with a girlfriend and we were driving out and I saw this tall, long, lean person and I say, 'Who is that?' And she says, 'I think that's Perez Hilton.' I said, 'No. I have to say something to him. I have to.'
"So I pulled up and we were sort of scoping each other out as I was pulling the car up," she continued. "I just rolled down the window and I was like, 'Hi.' And he went, 'Hi.' We stood there like two deer in headlights. And I just said, 'Come here. Just talk to me for a second.'
"It was one of those great moments. It was a lovely meeting and I was just like, 'Why are you so mean?'" she said.
Aniston, whom Hilton used to refer to as "Maniston," was a frequent target of his six-year-old website.
"She asked me, 'Why do you call me Maniston?'" Hilton said in a video posted on his website, in which he recounted the meeting. "She said that it hurt her and that it was mean."
"I told her all the excuses that I kept telling myself," he said in the video. "I would make myself feel better by saying things like what I told her, 'You're just a character, it's just entertainment, don't take it so seriously.'"
But as the conversation continued, the two began to see each other as human beings, not characters.
Perez Hilton Makes Peace with Jennifer Aniston
"There's something really great about putting a human being in front of another human being and then the reality that those words, even if it's for humor or effect or whatever, there's a human being behind all of that," Aniston told DeGeneres.
Hilton told ABCNews.com that he confided to Aniston about wanting to "be more positive and making more positive changes in my personal life."
The tipping point came two months later, after a rash of suicides by teenage bullying victims, and a video posted by Khloe Kardashian in which she called Hilton a bully.
In October, the self-proclaimed "Queen of All Media" announced on the DeGeneres show that he would no longer bully celebrities on his website.
"Over the last two weeks I have been doing everything I can to bring awareness to the teen suicides and gay bullying," Hilton told DeGeneres. "In doing so, a lot of people have called me a hypocrite and a bully myself and a big one... From now on I really want to be part of the solution and not part of the problem."
Since then, Hilton has eliminated all the "name calling, doodling inappropriate things on photos and outing celebrities," he told ABCNews.com.
"I have kept up my promise," he said. "I'm still going to have opinions and be critical, but in a fun and sassy way and not nasty and mean-spirited. I haven't really slipped up, either. I'm making an active effort every day to do this and be this way."
The change has not decreased the number of visitors to the site -- nor has it increased them either, Hilton said. But Hilton added he no longer feels a pariah in the gay community. "It's wonderful to be able to go to gay events and speak on MSNBC about marriage equality and not have as many people in my own community be embarrassed or ashamed of me.
Aniston has apparently noticed the change.
"He's kept it up too, which is good," the actress told DeGeneres. "I say good for him and keep it up."
Hilton, who had not planned to go public with the encounter, said he was surprised when Aniston did.
"I'm happy that she did, though," he said. "In that story, others may find hope and inspiration, seeing two people who previously did not really care for each other come to a place of peace and maturity. I wish her only the best and I thank her for the kind words."
Then, he added gleefully, "She even called me lean!"