The 20-year-old forward was due to see his previous deal expire at the end of June.
He will, however, be remaining on the books at Loftus Road for another 12 months.
Hitchcock will be hoping to force his way into Harry Redknapp's first team plans during that time.
He is yet to make his senior bow for QPR, but impressed last season during a loan spell at Bristol Rovers.
Despite being restricted to just seven starts for the League Two club, he netted three times in 17 appearances.