Atomu Tanaka (田中 亜土夢, Tanaka Atomu, born October 4, 1987 in Niigata, Japan) is a Japanese football player who plays for HJK Helsinki in the Veikkausliiga. He was a participant at 2007 FIFA U-20 World Cup in Canada and scored 1 goal in 3 appearances.
Born in Niigata. Tanaka was educated at and played for Maebashi-Ikuei High School in Guuma. While he was a high school student, he was chosen as one of the Designated Players for Development by J. League and JFA. Because of this status, He was able to register as an Albirex Niigata player while he was still eligible to play for his high school club. He played two league games for Albirex in the 2005 season. He made his debut on 27 November 2005 in a J. League away match against Nagoya Grampus.
After graduating from his high school in 2006, he officially signed with Albirex Niigata. His first appearance as a professional player came on 5 March 2006 in a league match against Kawasaki Frontale. His first professional goal came on 8 April 2006 in a league match against Ventforet Kofu.