John Legend to Appear at Democratic National Convention

Democratic big wigs are attempting to corral A-list celebs to show face at the Democratic National Convention -- and one person we know they've locked down is John Legend.

Sources with direct knowledge tell TMZ ... John is all in for an appearance at the convention in Chicago in a few weeks -- and while we know he's going to be participating front and center ... it's still a little hazy on how exactly he'll contribute.

In other words ... we're not sure if he'll just be speaking, singing/performing or a mix of both. Considering his political history though -- you can probably expect a little bit of everything.

As you know ... John is a longtime, and vocal, Dem who's been politically active in the last several presidential campaigns.

He and wife Chrissy Teigen were big supporters of President Joe Biden during his 2020 campaign, with John even performing at an Election Day eve rally in Philly for Biden.

He's since voiced his support for Vice President Kamala Harris. In fact, John was one of the first celebs to speak out on social media in her favor after Biden dropped his reelection bid.

He wrote ... "She's ready for this fight and I'm excited to help her in any way I can."

Looks like John is making good on that promise. Although convention planners tell us no final programming decisions have been made at this time, our sources say John's 100% on board.

Celebs have become fixtures at political conventions. Just look at the RNC in Milwaukee, where Amber Rose, Hulk Hogan and Kid Rock made showy appearances in support of Donald Trump.

No word on whether Chrissy and kids will be there, but considering they tend to roll as a unit -- it wouldn't be far-fetched to assume this might be a family affair.