They Don't Know is the second single off of Houston based rapper Paul Wall's debut album The Peoples Champ. The album's version of the song features Mike Jones. There is also a remix that features Lil Keke, Slim Thug, Big Hawk, Bun B, and Trae. A second remix features only Bun B. The video is a composite of both versions of the song featuring both Bun B & Mike Jones, where Paul Wall's second verse is shortened for Bun B's verse. Lil Keke, Slim Thug and Killa Kyleon made cameo appearances in the video. The chorus is made of various samples: "They don't know what that star about, they don't know what that barre about, they don't know what that candy car about or smokin' that joint about" - Sampled by UGK's 'Wood Wheel' "Texas is the home of the players and pimps" - Sampled by Slim Thug's ? "Showin' naked ass in the great state of Texas" - Sampled by DJ Screw's 'Pimpin' Anthem' "3rd coast born, I mean we're Texas raised" - Sampled by Fat Pat's '3rd Coast Raised' "Texas motherfucker that's where I stay" - Sampled by Pimp C's ?

"They Don't Know" redirects here. For the song by Savage, see They Don't Know (Savage song). "They Don't Know" is a song written by Kirsty MacColl. MacColl recorded it in 1979. It became popular on radio in the United Kingdom reaching #2 on the Airplay chart; however, complications involving a strike at her distributors prevented the single from being shipped and promoted properly preventing release of the single hence failing to chart.

In 1983, Tracey Ullman included a version on her debut album, You Broke My Heart in 17 Places, which was composed entirely of remakes. This song was the album's most successful single, charting in the top ten of various national charts. MacColl performed backing vocals on Ullman's version and keeping her original "bay-ay-be-ee" in the middle of the song, which went to #2 in the U.K., #8 in the U.S., and became the theme song for the final three seasons of Ullman's later television series Tracey Takes On.

The video for "They Don't Know" featured a cameo from Paul McCartney; at the time Ullman was filming a minor role in McCartney's film Give My Regards To Broad Street.

Indie band The Boyfriends covered the song as a b-side for their single Once Upon A Time.

Death Cab for Cutie lead singer Ben Gibbard often covers "They Don't Know" in live performance.