Doug Irwin was an American luthier best known for designing and building five custom electric guitars for Jerry Garcia of the Grateful Dead: Eagle, Wolf, Wolf Jr., Tiger, and Rosebud. Garcia first encountered Irwin's work in the early 1970s through an instrument originally built while Irwin was at Alembic, and the two developed a long collaboration that produced some of the most recognizable guitars in rock history. Tiger, which Garcia played as his primary instrument from 1979 to 1989, took Irwin more than 2,000 hours to build over roughly six years and later set a record at auction as one of the most expensive guitars ever sold.

Irwin's instruments are characterized by intricate inlay and woodwork, brass hardware, neck-through construction with exotic tonewoods, and elaborate onboard electronics. Rosebud, often considered his masterpiece, expanded on the Wolf design with onboard MIDI capability for triggering external synthesizers. Beyond Garcia's commissions, Irwin built basses for players including Phil Lesh and Oteil Burbridge, along with a small number of numbered limited-edition guitars, double-necks, and one-off custom builds such as the 1974 "Dollar Sign" guitar.

Operating as a small custom shop rather than a production brand, Irwin produced instruments in very limited quantities, with each guitar built largely by hand. His body of work occupies a singular place in the history of custom electric guitar building, and authentication of his instruments is handled through Irwin Certified.

Doug Irwin has 3 products cataloged on Equipboard, including Solid Body Electric Guitars. Their gear is featured by 2 artists, with the strongest followings in Rock and Folk, World, & Country. Notable users include Jerry Garcia and Derek Trucks.