Erik Jon Koch[4] (born October 4, 1988) is an American mixed martial artist who last competed in the Welterweight division of the Ultimate Fighting Championship.

Koch would later drop out of Washington High School (Cedar Rapids, Iowa)[7] to pursue a professional career in mixed martial arts.

Fighting primarily in Iowa, he amassed an undefeated streak of 8–0 before being signed to World Extreme Cagefighting.

Koch was scheduled to fight Wagnney Fabiano at WEC 43 on September 2, 2009,[10] but was forced to withdraw from the bout due to an undisclosed injury while training.

Koch defeated promotional newcomer Francisco Rivera via first-round TKO, earning Knockout of the Night honors.

[22] Koch faced The Ultimate Fighter 12 winner Jonathan Brookins on September 17, 2011, at UFC Fight Night 25.

After two consecutive losses, Koch returned to lightweight and faced Rafaello Oliveira on February 22, 2014, at UFC 170.

[35] However, Koch was forced from the bout with injury and replaced by promotional newcomer Andrew Holbrook.

[37] However, Koch pulled out of the bout in early December citing another injury and was replaced by Scott Holtzman.

[39] However, Proctor pulled out of the fight on April 21 citing injury and was replaced by Shane Campbell.

[42] However on August 11, Koch pulled out again due to injury and was replaced by promotional newcomer Jason Gonzalez.

[49] Koch was scheduled to face promotional newcomer Dwight Grant in a welterweight bout on December 15, 2018, at UFC on Fox 31.

[54] Koch was suspended by USADA for 18 months for testing positive for 3'-hydroxy-stanozolol, a metabolite of stanozolol, as the result of a urine sample collected on October 3, 2020.