Orton had come under fire after being cast as the lead in the third Marine movie due to his controversial real-life military background.
Cpl Mike Vinn served with Orton in the US Marine Corps andaccused the wrestler of deserting his company twice, leading to the star being dishonourably discharged and spending 38 days in jail.
The WWE has admitted to showing "poor judgement" in hiring Orton to star in Marine: Homefront. Orton's replacement for the film has not yet been announced.
Cpl Vinn has now told TMZ that he's pleased Orton will no longer be playing a heroic marine.
"On behalf of all the Marines from Aco 1/4 98-02, that were outraged to hear about Randy Orton portraying a Marine in the next movie Marine: Homefront, I'd like to thank the WWE for pulling Orton from the role when they heard about his disloyal service to the United States Marine Corps," Cp Vinn said.
He added: "[The WWE's decision] shows respect for not only the unit I had served in, but for every person that has ever defended this nation. Thank you WWE."
The original Marine film, which starred John Cena, proved to be the WWE's most successful film at the box office.
Wrestler Ted Dibiase Jr starred in a direct-to-DVD sequel in 2009.
> WWE's CM Punk challenges Chris Brown to fight over steroid insult
> Dwayne 'The Rock' Johnson: 'I still have something to prove in WWE'
Watch Randy Orton battle Dolph Ziggler below (US only):