Alys Margaret Thomas (born 10 October 1990) is a British professional swimmer.

She gained a gold medal and the 200m Butterfly Commonwealth games record in 2018.

She was born in 1990 and she went to Lady Eleanor Holles School in Hampton, London.

[1] She competed in the women's 100 metre butterfly event at the 2017 World Aquatics Championships.

[6] In April 2021, Thomas was named as a member of the British team to go to the postponed 2020 Olympics.