RCMP say both aircraft were flying parallel to each other from Carstairs to Red Deer on Sunday morning when the collision happened.
They say one of the aircraft crashed in a field while the other landed safely.
RCMP Const. Bethany Simpson says the aircraft were small, fully enclosed, single-engine planes that were built from kits.
Police say the Transportation Safety Board is taking over the investigation.
A spokeswoman for the safety board says investigators likely won't have more information to release until Monday.