Sir Robert Bryson Hall II (born January 22, 1990), known professionally as Logic, is an American rapper, singer, songwriter, and record producer from Gaithersburg, Maryland. He released his debut mixtape, Psychological: The Mixtape in December 2009 under the name Psychological, which he later shortened to Logic. He gained popularity following his Young Sinatra (2011) mixtape series; its third installment, Young Sinatra: Welcome to Forever (2013) received critical acclaim and led him to secure a recording contract with Def Jam Recordings. Logic's first two studio albums—Under Pressure (2014) and The Incredible True Story (2015)—both peaked within the top five of the U.S. Billboard 200 and received platinum certifications by the Recording Industry Association of America (RIAA).

Logic's next three albums — Everybody (2017), YSIV (2018) and Confessions of a Dangerous Mind (2019) — each debuted atop the Billboard 200. The former was supported by the Billboard Hot 100 top-three single "1-800-273-8255" (featuring Alessia Cara and Khalid), while the latter spawned the top-five single "Homicide" (featuring Eminem). After his sixth album No Pressure (2020), Logic retired from music; however, his career would continue with the release of his seventh mixtape Bobby Tarantino III (2021). His seventh album, Vinyl Days (2022) was his final release with Def Jam. His eighth and ninth albums, College Park (2023) and Ultra 85 (2024), were released independently.

Logic has received two Grammy Award nominations. As an author, he released the novel Supermarket (2019), which was accompanied with a namesake soundtrack album. The book became a New York Times Best Seller, although both works received generally unfavorable critical reception. He published his memoir, This Bright Future, in 2021. Logic is also a streamer and signed exclusively with Twitch in 2020, becoming the first musician to do so.