Houston, Texas - US gymnastics star Simone Biles has said she is delighted to be home after her tumultuous appearance at the Tokyo Olympics.

The 24-year-old flew into Houston on Thursday and was welcomed at the airport by crowds of supporters and relatives, including parents Ronald and Nellie and her sister Rachel.

Biles wrote on Instagram, "Houston, I’m home. Thanks for making sure I didn’t have to wait one more minute to see my family @united," giving props to her airline.

"Superhuman ability. Superhuman bravery," United Airlines captioned shots of the athlete, as they supported their "partner and friend."

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"Welcome home," the company said in their IG story.

Carrying a bouquet of flowers, Biles only briefly interacted with local media, saying she wanted to "have some space."

The legendary gymnast’s sister Rachel told a local station that the day was "very, very emotional. Good to have her back."

After leaving the airport, Biles headed to her nearby hometown of Spring in a convertible, cheered on by numerous fans who lined the road holding placards of support.

She posted an IG story later on Thursday night in the car, writing, "Feels good to drive again." In the snapshot, she is fittingly listening to the song She's Fire on her radio.

Biles' homecoming followed her dramatic appearance at the Games marked by withdrawals, psychological counselling, and family tragedy.

She had arrived with the expectation of equalling or even surpassing her historic quadruple gold medal haul from Rio in 2016.

But after a relatively underwhelming qualification process, she admitted she was experiencing mental health issues and "the twisties" – a phenomenon which temporarily affects an athlete’s spatial awareness.

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Biles also revealed her paternal aunt had died suddenly during the first week of the Games.

Daily medical evaluations and two sessions with a sports psychologist within the US team led to Biles being effectively withdrawn from her finals until she was cleared for beam, theoretically the least risky of the apparatuses and one which can be performed with the minimum impact on spatial elements.

She took a bronze medal in the beam, to go with her silver from the team competition.

Now she is home resting with her family, safe and sound, before she will go on an all-star gymnasts tour with Gold Over America next month.