James Leo Krause (born June 4, 1986) is an American entrepreneur and former mixed martial artist. He competed in the welterweight division of the Ultimate Fighting Championship (UFC). A professional from 2007 to 2020, Krause has made a name for himself fighting all over the United States, competing mainly in the Midwest region. Krause has also competed for organizations such as Bellator, WEC, the RFA, and Titan FC. He previously taught Brazilian Jiu Jitsu and mixed martial arts out of his formerly owned gym, Glory MMA & Fitness in Lee's Summit, Missouri. He was also founding a local promotion, Kansas City Fighting Alliance. He owns some Metro PCS stores in the Kansas City metropolitan area.

Krause was born in Newport News, Virginia, but moved to Odessa, Missouri, after his parents got divorced when he was two years old. At the age of seven, Krause began training in karate. Krause began attending Odessa High School in Missouri starting in 2001 where he competed in wrestling and graduated in 2004. Krause opted out of attending college, and instead began working full-time before finding MMA at the age of 19.^{[citation needed]}

Before turning professional in 2007, Krause had a successful amateur career with a record of 18–1, holding two championships, and for six consecutive months was ranked as the number one amateur in the country. On November 28, 2007, Krause made his long awaited professional debut for Kansas', Titan Fighting Championships, defeating Kevin Hengler via technical submission in the first round. Throughout 2008 and 2009, Krause fought all over the Midwest, mostly in Missouri, collecting a 10–0 record with all of his wins coming from stoppages.

In April 2009 Krause signed on with the World Extreme Cagefighting. He made his debut for the promotion on June 7, 2009, at WEC 41 against Donald Cerrone. Krause was a late-replacement for Rich Crunkilton. Krause lost the fight via first-round submission.

Krause then fought Ricardo Lamas on the preliminary card of WEC 44 on November 18, 2009. After being controlled on the ground for three rounds, Krause lost the fight via unanimous decision. Krause was released from his contract after going 0–2 for the promotion.

Krause signed with Bellator Fighting Championships in April 2010, replacing Ferrid Kheder in the Bellator Season Two Lightweight Tournament. His first bout of the tournament was originally slated for Bellator 15 but was instead moved to a week earlier and held on the Bellator 14 card. Krause fought Season One's runner-up, Toby Imada, losing via second-round armbar submission. The loss took Krause out of the tournament.

Krause was expected to compete on the Bellator 16 card against an unnamed opponent but was forced off the card due to an injury.

After being released from Bellator, Krause re-signed with Titan Fighting Championships. His return came at Titan Fighting Championships 17 on March 25, 2011, against Nathan Schut. Krause won the fight via TKO after connecting with a head kick.