TLC has racked up an impressive list of celebrities willing to dig into their family's history for all to see when it begins airing the eight-episode fourth season of "Who Do You Think You Are?" on Tuesday, July 23 at 9/8c.

"American Idol" champ Kelly Clarkson, "The Big Bang Theory" star Jim Parsons, E!'s late night host Chelsea Handler, movie star Chris O'Donnell and country singer Trisha Yearwood will appear on the show's upcoming season on the cable channel.

Back when TheWrap broke the news that TLC had picked up the docu-series after NBC canceled it, we reported that former "Up All Night" star Christina Applegate, "New Girl's" Zooey Deschanel and model Cindy Crawford had signed on for the series.

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Produced by Lisa Kudrow and Dan Bucatinsky's Is Or Isn't Entertainment and Shed Media, the series was canceled by NBC after its third season. Martin Sheen, Rob Lowe, Blair Underwood, Sarah Jessica Parker and Paula Deen are among those who appeared on the show's NBC run.

Ancestry.com will also continue as a sponsor and primary research tool on the series.

Watch the new promo below: