Finneas O'Connell (born July 30, 1997), also known mononymously as FINNEAS, is an American singer, songwriter, actor, and record producer. He grew up in Los Angeles, and began writing and producing songs at the age of 12. He is also known for his role as Alistair in the Fox TV series Glee. Finneas was born to parents Maggie Baird, an actress, and Patrick O'Connell and has mainly Irish and Scottish ancestry. His sister is singer Billie Eilish, for whom he co-writes and produces music. He is the lead singer and songwriter of the band The Slightlys, which has won awards and competitions in the Los Angeles area. He co-wrote and produced sister Billie Eilish's debut EP dont smile at me which peaked at 97 on the US Billboard 200.