George Clooney has thrown his support behind Kamala Harris ... which is really the least he could do after he penned an op-ed asking President Biden to exit the race.

Clooney endorsed the Vice President's new campaign in a statement shared with CNN Tuesday, where he praised Biden for being a true leader and "saving democracy once again."

He continued ... "We're all so excited to do whatever we can to support Vice President Harris in her historic quest."

Earlier in July, George called for a new nominee in an op-ed letter published in the New York Times ... where he slammed 46 for not being the same politician he once was -- citing the presidential debate and the George Stephanopoulos interview as evidence.

Clooney received quite a bit of backlash for the letter ... though, he wasn't alone in his sentiment -- other Democrats went on to make similar pleas. Within weeks, Biden ended his reelection bid, in which he endorsed VP Harris as his replacement.

In the aftermath of the announcement, several eyes turned to Clooney to see what he would do next ... with even "The View" cohost Ana Navarro calling on GC to write the Democrats a "big check" -- since he essentially sparked this whole thing.

Looks like word got back to George, as he is fully Team Harris now.

Since then, most of Hollywood has thrown their support behind Kamala ... including Cardi B, Barbra Streisand, Jamie Lee Curtis, Viola Davis, Kerry Washington, Charli XCX, among others.

KH's campaign claims they've raised over $100 million since its formal launch earlier this week ... the largest amount raised in a 24-hour period in presidential history. It seems Momala is on the move!!!