Douglas Kostynski (born February 23, 1963 in Castlegar, British Columbia) is a retired ice hockey centre. He was drafted by the Boston Bruins with the 186th overall pick in the 1982 NHL Entry Draft. He played 15 games for the Bruins, scoring 3 goals and an assist.
He played Tier II Junior "A" for the Abbotsford Flyers for part of the 1979-80 season and major junior for the New Westminster Bruins and the Kamloops Jr. Oilers from 1980 to 1983.
After being drafted by the Boston Bruins, Kostynski turned pro with the Hershey Bears in 1983-84. He was called up by the Bruins for brief spells in 1983-84 and 1984-85. He then played in 1985-86 and 1986-87 for the Moncton Golden Flames and in 1987-88 for the Adirondack Red Wings.
In 1988 Kostynski moved to Finland and played two seasons for SaiPa Lappeenranta. He retired in 1990.