Donald S. Martinez (1903-1955), was an American commercial fly tier, fly shop owner and fly angler. He is most noted for his development and promotion of the woolly worm fly and dry fly fishing in the Yellowstone National Park region. He operated a seasonal fly shop in West Yellowstone, Montana during the summers of 1932-1943. His West Yellowstone shop was eventually sold to Bud Lilly and became Bud Lilly's Trout Shop which still operates there today.
Martinez was also a founder of the Izaak Walton League and is credited with introducing dry fly fishing to Yellowstone National Park in the 1930s. To Martinez has been attributed the marketing of the Woolly Worm (imitation) lure for western waters. Northwest Fly Fishing Magazine named Don Martinez to its 'Pioneers & Legends' distinction in the fall of 2004, two years before Zane Grey. Don Martinez has also been featured in the book, Fly Fishing Pioneers & Legends of the Northwest. Born in Chicago and later relocating to southern California, Martinez was a real estate executive, and son of George D. Martinez and Alice Shillman Martinez. He and his spouse Nola had two children, David G. Martinez and Mary M. Martinez.