Warren Barnes Dunnell (1851-1931) was an American architect who primarily worked on buildings in Minnesota. Dunnell was born in 1851 in Norway, Maine. His parents moved to Minnesota in 1863 settling first in Winona and later moving to Owatonna. Dunnell attended the University of Minnesota in 1869 but later transferred to the Massachusetts Institute of Technology. He also studied at the École des Beaux-Arts in Paris.
Initially Dunnell worked for the federal government but he returned to Minnesota in the mid-1870s and found work with several other local architects including Samuel J. Brown and Abraham Radcliffe. In 1881 Dunnell established his own firm in Minneapolis focusing on churches, public buildings and institutional buildings such as schools and hospitals. Among the buildings he designed are the Fergus Falls State Hospital, the Minnesota Correctional Facility – Red Wing, the Minnesota State Public School for Dependent and Neglected Children and parts of the Minnesota Veterans Home complex. Dunnell's buildings included elements of various styles including Romanesque Revival, Beaux Arts and Châteauesque.
Dunnell died in 1931 and is buried at Forest Hill Cemetery in Owatonna.
- Lathrop, Alan K. (2003). Churches of Minnesota: An Illustrated Guide. University of Minnesota Press. p. 286. ISBN 9781452904405.
- Gardner, Denis (2004). Minnesota Treasures: Stories Behind the State's Historic Places. Minnesota Historical Society Press. p. 160. ISBN 0873514718.
- Three Dedications: Soldiers' Monument at South Sutton; Pillsbury Free Library at Warner; Margaret Pillsbury General Hospital at Concord (Concord: Republican Press Association, 1891)
- "Warren Dunnell (1851-1931)". Find a Grave. Retrieved 3 December 2014.