Olivia-Mai Barrett is an English actress from London, United Kingdom. She began her career in music videos and the Disney series Penny on M.A.R.S. in which she played the title role and Alex & Co. on the Disney Channel.

In 2019, she was the sole actress in the last of eight episodes of the BBC mini-series, Soon Gone: A Windrush Chronicle, a series showing life in the UK for successive generations of people with Caribbean heritage, as Michaela Williams. In The Observer, Kwame Kwei-Armah was quoted as saying "Her performance was incredible, I was amazed at how she brought such empathy and insight to the part". Barrett shares the same background as her character in the series, as her father is mixed-race and her grandfather Jamaican; the Windrush story is part of her family background.

In 2020 she starred in the film My Dad's Christmas Date.