Peter W. Hopkins (February 1, 1826 – February 7, 1879) was an American lawyer and politician from New York.
He was born in Clifford, Susquehanna County, Pennsylvania, the son of Peter Hopkins (c.1785–1879) and Mary Ann Hopkins (1789–1876). The family removed to a farm in New York when Peter was still an infant. He attended the common schools, worked on his father's farm, and then taught school in Owego. In 1846, he began to study law, and was admitted to the bar in 1850. During the American Civil War he fought with the 109th New York Volunteers, and became adjutant and quartermaster of the regiment.
In 1864, he married Julia Keeler (c.1840–1866). After the war he resumed the practice of law in Binghamton.
He was District Attorney of Broome County from 1868 to 1874; and a member of the New York State Senate (24th D.) in 1878 and 1879.
He died on February 7, 1879, at the Eldridge House in Albany, New York, of "apoplexy," and was buried at the Spring Forest Cemetery in Binghamton.