John Malcolm Breck (April 9, 1828 – February 21, 1900) was a businessman in Portland, Oregon, United States, who served as mayor of Portland from 1861 to 1862.

Breck was born in Berks County, Pennsylvania,[1] in 1828.

In 1850, he left Wisconsin for Oregon on the vessel Columbia.

[2] In 1857 and 1858 Breck was elected Assessor of Portland.

[5] Breck died at his home in Portland on February 21, 1900.