The planes hit each other over a heavily populated area and landed in a mass of fire, acrid smoke and debris. The accident took place near the small Aero Country Airport around 5.30pm.
McKinney police confirmed on social media that at least three people have died in the crash.
"Confirm 2 planes crashed and at least 3 fatalities," they posted on their official Twitter account.
It is not clear if the three fatalities are the pilots or people on the ground as authorities have not yet released their names.