John Black (born Jean Schwartz; August 16, 1830 – October 25, 1899) was a French American immigrant and Democratic politician.

He attended college in Metz before moving with his family to the United States in 1844, settling near Lockport, New York.

Black was active in politics, having served in the Wisconsin State Assembly, the Wisconsin State Senate, the Milwaukee Common Council, and, in 1878, as Mayor of Milwaukee for a two-year term, a Democrat in a city largely Republican at the time.

He appointed a fellow Democrat as police chief, who fired twenty-five Republican policemen (as part of the spoils system then prevalent).

"[3] Black was the Democratic nominee to the United States Congress in 1886, but was defeated by Henry Smith of the Union Labor Party.