Serena Williams held strong views on tennis, society as well as her rivals.

AFP Sport looks at some of the American's most memorable and occasionally controversial quotes:

"Are you looking at my titles?"

-- Message on the front of her T-shirt at Wimbledon in 2009. She had added three more Slam titles to her collection in the preceding 12 months but was still ranked number two in the world behind Dinara Safina who never lifted a major in her career.

"At first people said it would be fine, it would be all right but it turned out to be a lot more serious. If it had been left two days later it could have been career-ending – or even worse. They told me I had several blood clots in both lungs. A lot of people die from that."

-- On blood clots on her lung in 2010

"I love me. I've learned to love me. I've been like this my whole life and I embrace me. I love how I look. I am a full woman and I'm strong, and I'm powerful, and I'm beautiful at the same time."

-- Hitting out at body shamers

"She begins every interview with 'I'm so happy. I'm so lucky' – it's so boring. She's still not going to be invited to the cool parties."

-- On rival Maria Sharapova

"When I stop playing, it's not going to be because I'm sick of playing...It's going to be because I'm sick of practicing."

-- In 2013 when asked about her future

"Will I have to explain to my daughter that her brother is going to make more money doing the exact same job because he's a man? If they both played sports since they were three years old, they both worked just as hard, but because he's a boy, they're going to give him more money? How am I going to explain that to her?"

-- On equal prize money in tennis

"We see things that have been hidden for years; the things that we as people have to go through. This has been happening for years. People just couldn't pull out their phones and video it before."

-- On racism in the light of the emergence of the Black Lives Matter movement.

"I don't know. If I ever say farewell, I wouldn't tell anyone, so…"

-- After her 2021 Australian Open semi-final loss to Naomi Osaka

"I was heartbroken to have to withdraw feeling the extraordinary warmth and support of the crowd today when I walked on — and off — the court meant the world to me."

-- After an ankle injury forced her to withdraw during her first round match at Wimbledon in 2021.

"There comes a time in life when we have to decide to move in a different direction. That time is always hard when you love something so much. My goodness do I enjoy tennis. But now, the countdown has begun. I have to focus on being a mom, my spiritual goals and finally discovering a different, but just (as) exciting Serena. I'm gonna relish these next few weeks."

-- In July this year, discussing her imminent retirement.

"That ball was soooo in. What the heck is this? It was not out. Do I need to speak another language?"

-– To chair umpire Maria Alves during the 2004 US Open semi-final against Jennifer Capriati.

"I swear to God I'll take the ball and shove it down your throat."

-– Infamous tirade at a lineswoman who called Serena for a foot fault in the 2009 US Open semi-final.

...and the thoughts of her longtime coach:

"She changed tennis!. She brought an athletic dimension that there was not at all, she opened the doors, with her sister Venus, to a whole generation of players because it was a white sport. She invented tennis intimidation because she has a presence that makes others fear her."

-- Coach Patrick Mouratoglou to AFP in an interview in September on the eve of her 40th birthday.