Admiral-Lord Mountevans rules were a set of professional wrestling rules mainly used in the United Kingdom in the second half of the 20th century. Introduced in 1947, they were named after Edward Evans, 1st Baron Mountevans, who ordered a unified set of rules written up for professional wrestling in the British Isles to re-legitimise professional wrestling in the eyes of the public and the press. Professional wrestling in the United Kingdom had become discredited before World War II due to the prominence of the preceding "All In" style, which came to emphasise an "anything goes" style of presentation. Professional wrestling promoters in the United Kingdom rallied behind the Mountevans rules and radically altered how professional wrestling was presented in the United Kingdom thereafter. The style of wrestling under the Mountevans rules was advertised by promoters as Modern Freestyle Wrestling.
Mountevans rules would remain the predominant style of professional wrestling in the United Kingdom until the 1990s, when they were increasingly abandoned in favour of a style and presentation in line with American professional wrestling. Some UK promotions continue to use either the full rules and/or hybrid systems for all or selected matches.