Philip Ludwig "Louis" Breithaupt (8 November 1827 – 3 July 1880) was a German-born tanner and politician in Ontario, Canada.

[1] The son of Liborius Breithaupt, a tanner, and Catherine Goetze, he was born in Allendorf, Kurhessen, which today is a part of Germany.

[2] Liborius, with Louis assisting him, opened a small tannery in Buffalo located on Seneca Street, which mostly processed sheepskins.

His three eldest sons, Louis Jacob, William Henry, and John Christian, who would later become locally prominent in their own right, were born in Buffalo before the move, in 1855, 1857, and 1859 respectively.

Some of the American Block's earliest mercantile tenants included Tyson's Grocery and a boot and shoe store owned by William Niehaus, both occupying King Street storefronts.

[2] He suffered a significant setback that year when his tannery was destroyed by fire,[5] but he rebuilt and continued, and was elected as deputy reeve of Berlin.