John McNeill Sieburth

John McNeill Sieburth (2 September 1927 – 7 December 2006) was a Canadian-born biologist. Sieburth spent his early career studying birds, then turned his attention to marine microorganisms.

Sieburth was born on 2 September 1927 in Calgary, Alberta, and was raised in Vancouver, British Columbia. He graduated from University of British Columbia in 1949, subsequently earning a master's degree from Washington State University two years later, followed by a doctorate at the University of Minnesota in 1955, after which he began his teaching career at Virginia Tech within the school's veterinary department. In completing his Ph.D., Sieburth studied turkeys. His research interest later turned to penguins, then microorganisms. Sieburth left Virginia Tech in 1960 to accept a professorship in oceanography and microbiology at the University of Rhode Island, where he retired in 1991.

Sieburth met Janice Fae Boston while she was studying nutrition at Washington State. The couple married in 1950 and had five children, including chemist Scott Sieburth. John Sieburth died on 7 December 2006 in West Kingston, Rhode Island, from dementia complications. She authored Online Search Services in the Academic Library in 1988. She died in 2019.