Oliver Tree Nickell (June 29, 1993 – June 14, 2026) was an American singer, songwriter, music producer, rapper, and director. Born in Santa Cruz, California. In 2017, Tree signed with Atlantic Records after his song "When I'm Down" went viral, and released his debut studio album Ugly Is Beautiful on July 17, 2020. He gained international recognition with the songs "Life Goes On" in 2021 and "Miss You" in 2022.

He released his second studio album Cowboy Tears on February 18, 2022, his third studio album Alone in a Crowd on September 29, 2023, and his fourth and final studio album Love You Madly Hate You Badly on April 24, 2026.