The 2015 Indy Lights season was the 30th season of the Indy Lights open wheel motor racing series and the 14th sanctioned by IndyCar, acting as the primary support series for the IndyCar Series.

It was the first season for the Dallara IL-15 along with a Mazda MZR-R turbocharged 4-cylinder engine, developed by Advanced Engine Research.

The championship was contested over 16 races, starting on March 28 at St. Petersburg, Florida and ending on September 13 at Mazda Raceway Laguna Seca.

[18] Iowa was added in place of Pocono, whereas Sonoma was replaced by a standalone round at Laguna Seca.

The rounds at St. Petersburg and Toronto were expanded to double-headers, therefore the number of races increased to 16.