Serena Williams has described her sister Venus as her "hero" ahead of the release of the highly-anticipated King Richard biopic.

The Williams sisters joined actor Will Smith for an interview with Entertainment Weekly, during which they discussed the upcoming film King Richard.

The biopic follows Venus and Serena as they begin to make a name for themselves in tennis, documenting their rise to the icons they are today.

Smith plays Richard Williams, who coached his daughters as children and helped them to greatness.

"When we heard that Will wanted to do it, it was like, 'Oh my God this movie is going to be the real deal'," said Venus, a seven-time Grand Slam winner.

"Whatever film he's in, it's the real deal. We got the sense of this is gonna be big, this is gonna be a serious film."

She added: "I love that it captured the innocence — the innocence we still hang on to, actually. It's kind of difficult for me to say, 'Oh, this film shows me.' Because me is Serena. Me is my sisters.

"And there's no me without her, and I could have never done what I've been able to achieve on the court without her because I was also watching her and learning."

Serena was also full of praise for her sister, who is 15-months older and was the first of the siblings to compete on the WTA Tour.

"I feel completely different than Venus," she said. "Actually, I feel like the film actually tells her story, in a way that no one can ever really tell what she went through in being the first Black player to really step out there.

"You see the impact that it has had and all the people that are coming up after myself and Venus. There would be no Serena if there wasn't a Venus.

"She was my hero and she still is my hero. She'll do something and I'm like, 'I'm doing that too.' She's still my hero, she really was able to open the way for me and go through doors.

"Even though I was right behind her, it's still if you think about opening the door, [for] the second person it's a lot easier. Venus is so humble, she doesn't really take credit for that. She burst open that door and I ran through."

The 40-year-old Serena, who has 23 Grand Slam titles to her name, took a short break from playing in 2017 to give birth to her daughter Alexis Olympia Ohanian Jr.

She has now returned to the court and is seeking a record breaking 24th Grand Slam title.

The tennis legend revealed she sees King Richard as a way to explain her incredible career to her daughter.

"She gets to see what Mommy was like," Serena said. "I always wondered how I would explain my life. Like, how will I even start that conversation? This is the perfect way."

Venus and Serena are played by actresses Saniyya Sidney and Demi Singleton, respectively. King Richard is released in the UK on November 19th.