Finneas O'Connell, also known mononymously as FINNEAS, is an American singer, songwriter, musician, actor, and record producer. He has released several singles and has written music for other artists, including his sister Billie Eilish.

As an actor, FINNEAS starred as Shane in the independent film Life Inside Out (2013). He is also known for his role as Alistair in the Fox TV series "Glee." In 2011, he portrayed Spencer in the film Bad Teacher.

He also had a recurring role on ABC's "Modern Family" and appeared in two episodes of "Aquarius." FINNEAS was born to parents Maggie Baird, an actress, and Patrick. FINNEAS and has mainly Irish and Scottish ancestry.

FINNEAS grew up in Los Angeles and began writing and producing songs at the age of 12. 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 Don't Smile at Me which peaked at 14 on the US Billboard 200. FINNEAS served as producer and the only other songwriter on Billie Eilish's debut album, When We All Fall Asleep, Where Do We Go?, which debuted at #1 in the US and UK charts.

FINNEAS' first single, "New Girl," was released in 2016. The music video to the single was released in 2019. That same year, FINNEAS played his first sold-out shows as a headliner in New York in Los Angeles.

FINNEAS was nominated for the Grammy Award for Non-Classical Producer of the Year at the 2020 Grammy Awards. That year, along with sister Billie, he was also up for Record of the Year and Song of the Year with "Bad Guy" and Album of the Year and Best Engineered Album, Non-Classical.