A significant number of intermediate age clusters ( 1 - 2 Gyr ) in the Magellanic Clouds appear to have multiple stellar populations within them , derived from bi-modal or extended main sequence turn offs . If this is interpreted as an age spread , the multiple populations are separated by a few hundred Myr , which would call into question the long held notion that clusters are simple stellar populations . Here we show that stellar rotation in stars with masses between 1.2 - 1.7 M _ { \odot } can mimic the effect of a double or multiple population , whereas in actuality only a single population exists . The two main causes of the spread near the turn-off are the effects of stellar rotation on the structure of the star and the inclination angle of the star relative to the observer . Both effects change the observed effective temperature , hence colour , and flux of the star . In order to match observations , the required rotation rates are 20-50 % of the critical rotation , which are consistent with observed rotation rates of similar mass stars in the Galaxy . We provide scaling relations which can be applied to non-rotating isochrones in order to mimic the effects of rotation . Finally , we note that rotation is unlikely to be the cause of the multiple stellar populations observed in old globular clusters , as low mass stars ( < 1 M _ { \odot } ) are not expected to be rapid rotators .