The trip to West Yorkshire to face a fellow Championship side is North End's reward for beating Morecambe 3-1 at Deepdale on Tuesday night.
It is a tough draw, Leeds having won their first three games of the season under new manager Marcelo Bielsa.
They beat Bolton 2-1 to go into the hat for the second round.
North End and Leeds have only played two games against one another in this competition.
In October 1967, the sides drew 1-1 at Deepdale, with Leeds winning the replay 3-0.
The tie will be played in the week commencing August 27, less than a month before Preston are due to visit Elland Road in the Championship.