Giovanno Jimenez, 26, pleaded guilty to two felony counts of unlawful sexual intercourse with a minor and one felony count of lewd acts on a child.
Jimenez also received three years of formal probation with sex offender status and was ordered by the court to stay away from the victim.
Investigators said Jimenez had a relationship with a Valley High School girl between July 17 and Aug. 20, 2008, when she was 14 to 15 years old.
Police said they began investigating the case after receiving a complaint from a concerned parent.