Mervyn Bunter is a fictional character in Dorothy L. Sayers's novels and short stories. He serves as Lord Peter Wimsey's valet, having been Wimsey's batman during the First World War. Bunter was partially based on the fictional valet Jeeves, created by P. G. Wodehouse.

Sayers wrote a number of novels and short stories concerning the adventures of a fictional private detective called Lord Peter Wimsey, beginning with a Sexton Blake story she wrote in 1920.

The first Wimsey novel, Whose Body?, was published in 1923, and the last by Sayers alone, Busman's Honeymoon, was published in 1937. Further stories based on original material were published under the authorship of Sayers and Jill Paton Walsh, the last appearing in 2013. The original stories written by Sayers take place between 1921 and 1937; the continuation novels by Walsh extend through the Second World War and into the 1950s.

Mervyn Bunter is Wimsey's manservant. Sayers admitted having partially based Bunter's character on P. G. Wodehouse's Jeeves.

Bunter ensures that his master is dressed well. He is knowledgeable about cuisine, drinks, cigars, and social etiquette.

Bunter is solemn and dignified, with occasional understated sarcasm. He uses carefully correct and sometimes stilted English. He has a talent for music hall mimicry, and assists Wimsey in purchasing rare books and solving crimes.

Bunter occupies a high social position among domestic staff owing to his role as a valet. He is referred to as "Mr Bunter" by all other servants and tradesmen. His dress sense and manners command respect from his colleagues and impress cooks and maids.

He possesses a calmness which is broken only two occasions. In The Nine Tailors Bunter becomes upset after a maid is caught polishing a beer bottle taken as evidence. In Busman's Honeymoon, he becomes furious when Mrs Ruddle stands all the bottles upright and washes them.