John Aitken was named the 23rd superintendent of Shelby County Schools (SCS) on July 1, 2009. He was named to the position by the Shelby County School Board of Education after serving in the role of Assistant Superintendent of Student Services, Leadership & Safety during the 2008-09 school year.

Aitken guided SCS to consecutive State Report Cards with all A's in Academic Achievement in each of his first three years as superintendent. Additionally, he has been credited by a national review team for fostering “a culture of collaboration, respect and trust throughout the district and among its stakeholders” – a key commendation in SCS becoming Tennessee’s largest school system to be recommended for District Accreditation in 2011-12. In April of 2012, Aitken was recognized by the Tennessee PTA as the state's Outstanding Superintendent of the Year. The same year, he was presented with the PTA's National Achievement Award.

Aitken joined Shelby County Schools in 1983 as an Advanced Math and Geometry teacher at Collierville High School. He spent nine years in the classroom before entering the leadership ranks as an assistant principal at Houston High School. In 1997, Aitken opened his accomplished 11-year tenure as principal of Houston High School, elevating the school to premier status for academics, athletics and fine arts in Tennessee during that span. While at Houston, he was named Administrator of the Year by the Tennessee Association of Student Councils (TASC) and chosen by the statewide PTSA as Tennessee's Principal of the Year in 2008. Aitken was also named School System Administrator of the Year by the Tennessee Secondary School Athletic Association (TSSAA) in 2008-09 and has twice received the A.F. Bridges Principal of the Year honor from the TSSAA (1998-99 & 2005-06).