U.P.O. were an American post-grunge group from Los Angeles, California, formed in 1997 by vocalist Shawn Albro (Wicked Teaze) and guitarist Chris Weber (Hollywood Rose) after they met at England's Reading Festival. After a demo attracted major-label interest, they added bassist Ben Shirley and drummer Tommy Holt to the group's lineup.
After signing with Epic Records, they released debut album No Pleasantries, produced by Rick Parashar, in 2000. The albums lead singles, "Godless" and "Feel Alive", charted at numbers 5 and 25 respectively on the Billboard Mainstream Rock Charts. After touring extensively with the likes of Linkin Park, Slipknot, Nickelback, Godsmack and 3 Doors Down, the group went on hiatus in 2002. During that time, Albro, along with other singers, auditioned to become the singer for Velvet Revolver.
In 2004, the group returned, releasing The Heavy, produced by Rick Parashar, on Nitrus Records. Lineup changes followed with both Shirley and Holt departed the group, replaced by bassist Zoltan Bathory and drummer Philippe Mathys while Logan (Deadly Motor Vehicles) was added as the group's second guitarist. During a show, guitarist Weber suffered a seizure and was later diagnosed with a meningioma brain tumor. The group briefly performed without Weber before eventually going on another hiatus.
In 2005, Bathory left the group to form the successful metal group Five Finger Death Punch while Mathys is currently the drummer for Hydrovibe.