Hella is an American math rock band from Sacramento, California. The primary members of the band are Spencer Seim on electric guitar and Zach Hill on drums. The band expanded their live band by adding Dan Elkan on vocals, rhythm guitar, sampler and synthesizer and Jonathan Hischke on synth bass guitar for their 2005 tour. In 2006 they reformed as a five-piece line-up including Seim, Hill, Carson McWhirter, Aaron Ross & Josh Hill. In 2009, the band was reduced back to core members Hill and Seim.

Math rock is a style of alternative and indie rock with roots in bands such as King Crimson and Rush. It is characterized by complex, atypical rhythmic structures, counterpoint, odd time signatures, and extended chords. It bears similarities to post-rock.