Mr Mulliner is a fictional character from the short stories and novels of P. G. Wodehouse, who is widely regarded as one of the great comic writers of the 20th century, once described as "English literature's performing flea."

Mulliner is an habitué of the Angler's Rest, and his fellow drinkingmen are identified only by their beverages. (Hot Scotch and Lemon is Mulliner himself.) Like his fellow Wodehousian the Oldest Member, Mr Mulliner can enter any conversation and turn it to a reflection on a notable event from his recollection, and begin spinning his tale.

The tales of Mulliner are unique in that they all happen to involve some blood relation. Mulliner's parents, siblings, and progeny must have been fairly fecund, as there are dozens upon dozens of cousins, nieces, and nephews with remarkable life experiences to be shared. These stories are mainly about love lost and found; about fortunes made and failed; and opportunities sought and missed; they take place across the globe, though the English Country House is the setting for many.

Though Mulliner's character is never revealed beyond his large family and choice of beverage, he has many books and stories in his name:

• Meet Mr Mulliner (1927)
• Mr Mulliner Speaking (1929)
• Mulliner Nights (1933)

Stories are also scattered in other volumes, such as Lord Emsworth and Others. Many are collected in The Mulliner Omnibus (also published as The World of Mr Muliner)