Mark Ryden (born January 20, 1963) is an American painter who is considered to be part of the Lowbrow (or pop surrealist) art movement. He was dubbed "the god-father of pop surrealism" by Interview magazine. In 2015, Artnet named Ryden and his wife, painter Marion Peck, the king and queen of Pop Surrealism.

Ryden has been described as a "relentless kitsch meister working in the tradition of Bosch, Dalí, and Little Golden Books" and a master of Lowbrow style. His work has been described as having a pop-surrealist style that contains a nightmarish quality. His inspirations include "old children’s books, interesting product packages, toys, photographs, medical models, skeletons, shells, minerals, and religious statues." His album and single artwork for musicians includes Aerosmith's "Love in an Elevator" (1989), Michael Jackson's Dangerous (1991), Red Hot Chili Peppers' One Hot Minute (1995), Jack Off Jill's Clear Hearts Grey Flowers (2000), and Tyler, the Creator's Wolf (2013).

Ryden was born in Medford, Oregon on January 20, 1963, to Barbara and Keith Ryden, and was raised in Southern California. His father was a painter who also restored and customized cars. He has two sisters and two brothers: his brother Keyth is also an artist and works under the name KRK. Ryden graduated from the Art Center College of Design in Pasadena in 1987.

From 1988 to 1998, Ryden worked as a commercial artist. During this period, he created album covers for prominent musicians, including Danger Danger’s debut eponymous album; Warrant's debut album Dirty Rotten Filthy Stinking Rich; Michael Jackson's Dangerous; the 4 Non Blondes' Bigger, Better, Faster, More!; the Red Hot Chili Peppers' One Hot Minute; Scarling.’s Sweet Heart Dealer and their alternative vinyl cover of So Long, Scarecrow; Jack Off Jill's Clear Hearts Grey Flowers; the Screaming Trees' Uncle Anesthesia; Marcy Playground's Shapeshifter; and Aerosmith's "Love in an Elevator". He also created book covers, including the Stephen King novels Desperation and The Regulators. In 1994, Robert Williams featured Ryden's work on the cover of Juxtapoz, a magazine devoted to "lowbrow art", which helped launch Ryden to greater success.

Ryden's solo debut show entitled "The Meat Show" was in Pasadena, California in 1998. Meat is a recurring theme in his work. In a 2010 interview, Ryden stated, "There seems to be a complete disconnect between meat as food and the living, breathing creature it comes from. I suppose it is this contradiction that brings me to return to meat in my art."

A mid-career retrospective, "Wondertoonel", which refers to a cabinet of curiosities or Wunderkammer ("wonder-room"), was co-organized in 2004 by the Frye Art Museum in Seattle and the Pasadena Museum of California Art. It was the best-attended exhibition since the Frye Art Museum opened in 1952, and broke attendance records in Pasadena. Debra Byrne, then-curator of the Frye, placed Ryden's work in the camp of the carnivalesque—a strain of visual culture rooted in such works as Hieronymous Bosch’s Garden of Earthly Delights.

In 2007, "The Tree Show" opened at the Michael Kohn Gallery, Los Angeles. In this show, Ryden explored the contemporary human experience of nature. He explained, "Some people look at these massive trees and feel a sort of spiritual awe looking at them, and then other people just want to cut them up and sell them, they only see a commodity". Ryden has created limited editions of his art to raise money for the Sierra Club and Nature Conservancy.

In 2009, Ryden's exhibition "The Snow Yak Show" was shown at the Tomio Koyama Gallery in Tokyo.