James Herbert Sinclair (October 9, 1871 – September 5, 1943) was a U.S. Republican politician.

James Sinclair
Member of the U.S. House of Representatives from North Dakota's 3rd district
In office March 4, 1919 – March 3, 1933
Preceded by	Patrick Daniel Norton
Succeeded by	District abolished
Personal details
Born	James Herbert Sinclair October 9, 1871 St. Marys, Ontario, Canada
Died	September 5, 1943 (aged 71) Miami, Florida, U.S.
Political party	Republican

He was born near St. Marys, Ontario, Canada and moved to Dakota Territory in 1883. He was elected to North Dakota's State House of Representatives between 1915 and 1919 and then as a Republican member of North Dakota's congressional delegation for 8 consecutive terms between 1919 and 1935.