Cudahy was born on St. Patrick's Day in Callan, County Kilkenny, Ireland. A few months after he was born, his family moved to Milwaukee, Wisconsin. He worked his way up at the Plankinton and Armour meat packing plant in the Menomonee River Valley, becoming the superintendent in 1874. In 1888, the owner, John Plankinton, transferred the company to Patrick and his brother, John. The company became known as "Cudahy Brothers." The company changed its name to "Patrick Cudahy, Inc." in 1957, long after Cudahy's death.
In 1892, Cudahy moved the company to a 700 acre (2.8 km²) plot of land south of Milwaukee which he and his brother John bought for the purpose. This land was in the former Town of Lake, which is now divided between the municipalities of Milwaukee, St. Francis, and Cudahy.
Cudahy "had a bittersweet relationship with the village of Cudahy" in part because he supported temperance and "fought against liquor". He "argued with the Cudahy Common Council about the spread of taverns in the village", although he also worked to start assist business development and the construction of a new library. He said, "It is a source of satisfaction to me to look over those 25 years and see what has been accomplished, but I would feel much better if there were not the antagonistic spirit in Cudahy which seems to prevail to a great extent among its citizens."
Patrick Cudahy is buried at Calvary Cemetery in Milwaukee.
Patrick Cudahy's family includes:
Patrick Cudahy, Sr., father
- Patrick Cudahy, Jr., self
- John Clarence Cudahy (1887-1943), son (lawyer, real estate broker, and U.S. ambassador to Poland, Ireland and Belgium)
- Michael Cudahy, son (President of Patrick Cudahy, Inc from 1919 onwards)
- John Cudahy (1843-1915), brother (silent partner in the meat packing plants, Milwaukee and Chicago; Louisville self)
- Michael Cudahy (1841-1910), brother (president of Armour-Cudahy company, co-founder of Cudahy Packing Company (Omaha), and the city of Cudahy, California
- Edward Aloysius Cudahy, Sr. (1860-1941), brother, co-founder Cudahy Packing Company (Omaha)
- Edward Aloysius Cudahy, Jr. (1884-1961), nephew
- Cudahy, Patrick 1849 - 1919 - Dictionary of Wisconsin History - Wisconsin Historical Society
- "Saddle and Sirloin Portrait Catalogue" - North American International Livestock Exposition - (Adobe Acrobat *.PDF document)
- Sherman, Jeff. "Milwaukee Talks: Michael Cudahy" - OnMilwaukee.com - August 28, 2002
- Patrick Cudahy and Michael F. Cudahy WISCONSIN MEAT INDUSTRY HALL OF FAME University of Wisconsin-Madison
- Cudahy, Patrick. Patrick Cudahy: his Life, Milwaukee: Burdick & Allen, 1912.