
Art
Paul Julian (June 25, 1914 – September 5, 1995) was an American background animator, sound effects artist and voice actor for Warner Bros. Cartoons. He worked on Looney Tunes short films, primarily on director Friz Freleng's Sylvester and Tweety Bird shorts. During his time at Warner, Julian provided the vocal effects of the Road Runner.
[biography (excerpted) from Wikipedia]

Coyote vs ACME
as Road Runner (voice) (archive sound) (uncredited)

Flash in the Pain
as Road Runner (voice) (archive footage)

The Whizzard of Ow
as Road Runner (voice) (archive footage)

Superior Duck
as Road Runner (voice) (archive sound) (uncredited)

Tiny Toon Adventures: How I Spent My Vacation
as Road Runner (archive sound) (uncredited)

The Looney Tunes Hall of Fame
as The Roadrunner (voice)

The Bugs Bunny/Road Runner Movie
as Road Runner (voice)

The Wild Chase
as Road Runner (voice)

Hare-Breadth Hurry
as Bugs Bunny imitating the Road Runner (voice)

To Beep or Not to Beep
as Road Runner
Zipping Along
1953