Oliver Alexander Thornton (born 15 July 1990) is an English singer, actor and LGBT+ activist. He rose to prominence as the lead singer of the pop band Years & Years who achieved two number one albums on the UK Albums Chart, a number one single and five top ten entries on the UK Singles Chart. Between 2021 and 2023 he continued to release music under the Years & Years name until their dissolution in 2024. As an actor, he rose to critical acclaim for his performance as Ritchie Tozer in the Channel 4 drama series It's a Sin (2021). For his portrayal he was nominated for a British Academy Television Award for Best Actor and the Critics' Choice Television Award for Best Actor.
Alexander is set to represent the United Kingdom in the Eurovision Song Contest 2024 in Malmö, Sweden with his song "Dizzy", which marked Alexander's first release under his own name.