Rob Schneider was one of millions to share their condolences following Dikembe Mutombo's death ... but his tribute to the legend stuck out in particular -- as he used the tragic news to push his anti-vax stance.

The comedian went to X to mourn Mutombo's passing on Monday ... starting it off by saying, "Rest in Peace..."

Many wish he would've just left it at that ... as the rest of his post -- which quoted a video Mutombo made in 2021 to promote the Covid vaccine -- speculated if getting the jab had anything to do with the former All-Star's death.

As we previously reported, Mutombo succumbed to brain cancer ... a battle he went public with back in 2022.

Schneider sarcastically said it was "just (another) coincidence" that someone who got the vaccine died at just 58 ... and said he'll continue to tell everyone he knows not to get the vaccine.

Schneider's post has resulted in hundreds of responses ... with the consensus being it was a disgusting move.

One user said, "He had brain cancer. So your correlation ain’t correlating," while another added, "Bro just stop with the propaganda. Its old."

Another mentioned Schneider's toxic relationship with his daughter, Elle King -- "No wonder your own child thinks you’re a f***ing lowlife failure."

Schneider hasn't been shy about his beliefs ... so whether you agree with him or disagree, don't expect him to back down.