Jon Voight Credits Granddaughter With Helping Mom Angelina Jolie Win Tony

Jon Voight's super stoked his daughter Angelina Jolie won her first Tony Award ... a win he says may not have happened had his granddaughter not found the play!

We caught up with the legendary actor at LAX and asked about his daughter's big win for producing 'The Outsiders.' JV's over the moon for his kiddo.

Voight explains how Angie got involved with the project ... crediting his granddaughter Vivienne for watching the play multiple times before it landed on Broadway and convincing her mom to check it out.

Voight says Jolie saw it and fell in love with the show ... eventually calling him on the set of Francis Ford Coppola's "Megalopolis" to tell him she signed on to produce.

Jon says he sees the story as a clear sign Vivienne's got good taste in this arena ... and suggests she could one day be a Broadway producer herself.

Plus, check out the clip to hear what Jon says the directors of 'The Outsiders' think of Vivienne ... sure sounds like Viv's ready to follow in her mom's footsteps.

She's already got her first credit under her belt ... as we told you, Vivienne was a producer's assistant in the show, credited under the name "Vivienne Jolie" -- asking to drop "Pitt" like her sisters Shiloh and Zahara.

She hit up the Tonys with her mom -- skipping a possible Father's Day hang with Dad Brad Pitt ... looking in her element as the two walked the red carpet in matching teal ensembles.