Chuck Norris Honored by Sylvester Stallone, Dolph Lundgren

The legendary martial arts film star Chuck Norris has died ... and tributes have begun to pour in from fellow Hollywood badasses.

Dolph Lundgren -- who worked with Chuck on "The Expendables 2" -- posted a tribute on Instagram, including a heartfelt caption about what the late actor meant to him ... and Sylvester Stallone, another 'Expendables' costar and contemporary action star, also honored Chuck in a post.

Along with a BTS picture of the action duo, Dolph wrote ... "Chuck Norris is the champ. Ever since I was a young martial artist and later getting into movies, I always looked up to him as a role model. Someone who had the respect, humility and strength it takes to be a man. We will miss you, my friend. ✨"

Stallone wrote ... "I had a great time working with Chuck. He was All American in every way. Great man and my condolences to his wonderful family."

As we reported ... Chuck died Thursday morning in Hawaii, according to the family, who said, "It is with heavy hearts that our family shares the sudden passing of our beloved Chuck Norris yesterday morning. While we would like to keep the circumstances private, please know that he was surrounded by his family and was at peace."

TMZ broke the story ... Chuck was hospitalized either Wednesday or Thursday, and it seemed sudden, because a source who had spoken with Chuck on Wednesday said he had been working out and was in an upbeat, jovial mood.

The legend was 86.

RIP