Nicholas Diller Fratt (January 25, 1825 – November 12, 1910) was an American businessman, Democratic politician, and Wisconsin pioneer.

Nicholas D. Fratt was born January 25, 1825, in the town of Watervliet, in Albany County, New York.

Two years later, his brother, Francis, arrived from New York and took the place of Herrick as his partner in the business.

Fratt lived on his farm until 1894, when he moved into the city and bought a home on College Avenue.

In 1874, he was the Democratic candidate for the United States House of Representatives for Wisconsin's 1st congressional district, losing to incumbent Charles G. Williams.

Duffes had been born near Aberdeen, Scotland, and immigrated with her parents, in 1835, first to Canada, then to Illinois, and, in 1840, to Racine County.