| John Plant Gaynor | |
| Nationality: | Irish American |
| Birth Date: | circa 1826 |
| Birth Place: | Dublin, Ireland |
| Death Date: | June 9, 1888 |
| Death Place: | Oakland, California |
| Significant Buildings: | E. V. Haughwout Building |
John P. Gaynor (circa 1826–1888) was an Irish American architect practicing in New York City and San Francisco during the nineteenth century.
John Plant Gaynor was born circa 1826 in Dublin, Ireland. He was the son of surveyor John P. Gaynor, and likely received his early architectural training in the architectural school of the Royal Dublin Society.[1] In 1849 he immigrated to the United States, and practiced architecture in Brooklyn and New York beginning in 1851. There he was best known for the design of the E. V. Haughwout Building, a cast-iron fronted building completed in 1857. In 1863 he relocated to San Francisco, where he designed several large hotels and office buildings, most prominently the original Palace Hotel, completed in 1875 and destroyed in 1906.[2] His clients included the financiers William C. Ralston and Asbury Harpending. Gaynor retired in the mid-1880s and retired to his home in Oakland, where he died June 9, 1888.[3]
Gaynor frequently utilized cast-iron elements in his architecture, both in New York and San Francisco. His E. V. Haughwout Building in New York City, completed in 1857, was thought by preservationist Margot Gayle to be "The most celebrated of the cast-iron buildings still standing in New York City." He also designed the first cast-iron buildings in San Francisco.[4] Though much of his work has been destroyed, several of his remaining buildings have been listed on the United States National Register of Historic Places.