Andrew Robert Nielsen (born October 6, 1982) is an American rapper, known by his stage name MC Lars. He is the self-proclaimed originator of "post-punk laptop rap". He has recorded for Truck Records in the UK and his Laptop EP is licensed to Sidecho Records in the USA. He was formerly known as MC Lars Horris but changed his pseudonym to MC Lars in 2004 for purposes of simplicity. MC Lars currently resides in California.

He attended Stevenson School and was the co-founder of the Monterey Bay Area punk rock band Amphoteric. He would later leave and the group would switch directions and gain a progressive metal following (especially amongst Internet listeners). Although the line-up has changed entirely, the group still resides in central California and continues to release albums independently.