Leolyn Dana Wilgress, CC (October 20, 1892 – July 21, 1969) was a Canadian diplomat.

Born in Vancouver, British Columbia, to Henry T. and Helene M. (Empev), Wilgress was educated in Vancouver, Yokohama Japan, Victoria and at McGill University.

He became Director of the Commercial Intelligence Service in Ottawa in 1932; was an adviser at the Ottawa Imperial Conference in 1932, an adviser at the World Economic Conference at London in 1933; a negotiator in Washington for Canada–U.S.

In 1953 he received a Doctor of Laws, honoris causa from the University of British Columbia and in 1967 was made a Companion of the Order of Canada.

Wilgress died in 1969, and was interred in the Capital Memorial Gardens in Ottawa.