Justin Timberlake Jacked Our Dreamy Music ... Cirque du Soleil Sues

Justin Timberlake and Timbaland love them some Cirque du Soleil ... so much so, they jacked some of its music for one of JT's tune, at least according to the performing troupe.

Cirque filed a lawsuit against Timberlake and his producer for their song "Don't Hold the Wall" ... from the "20/20 Experience" album. Cirque thinks the hitmakers sampled a tune called "Steel Dreams."

Yes, Cirque does more than acrobatics ... it actually dropped an album in 1997.

It wants a cut of all profits Justin and Timbaland made off 'The Wall.' Unlike most JT songs, it was no commercial success -- never cracking Billboard's Hot 100.