Peter Robert Livingston was born on October 3, 1766 in New York City. He was the son of Robert James Livingston (1725–1771) and Susanna (née Smith) Livingston (1729–1791), daughter of Chief Justice William Smith (1728–1793). His brothers were Col. William Smith Livingston (1755–1795) and Judge Maturin Livingston (1769–1847). They were among the many great-grandchildren of Robert Livingston the Younger (1663–1725), through their grandfather, James Livingston (1701–1763), Younger's eldest son.
Livingston practiced law. His nephew, Francis Armstrong Livingston (1795–1830), lived with him in Rhinebeck, where Francis had a law office, and until Francis' wedding to Emma Charlotte Kissam in 1817.
He was a member of the New York State Senate (Southern D.) from 1815 to 1822, sitting in the 39th, 40th, 41st, 42nd, 43rd, 44th and 45th New York State Legislatures.
In 1823, he was a member of the New York State Assembly for Dutchess County, and was elected Speaker as a Democratic-Republican/Bucktail, with 117 votes out of 123.
From 1826 to 1829, he was again a member of the State Senate (2nd D.), sitting in the 49th, 50th, 51st and 52nd New York State Legislatures.
In 1828, when Lieutenant Governor Nathaniel Pitcher succeeded to the governorship after the death of Gov. DeWitt Clinton, Livingston was elected President pro tempore of the State Senate and became Acting Lieutenant Governor of New York.
He was again a member of the State Assembly, Columbia County in 1839 and was a delegate to the Whig National Convention from New York in 1839 where he served as Convention Vice-President.
He married his cousin, Joanna Livingston (1759–1827), the ninth child of Judge Robert Livingston (1718–1775) and Margaret (née Beekman) Livingston (1724–1800). She was the sister of Chancellor Robert R. Livingston (1746–1813), a member of the Committee of Five that drafted the Declaration of Independence, and Edward Livingston (1764-1836), a U.S. Senator and the 11th U.S. Secretary of State. They had no children.
He was originally buried at the Dutch Reformed Church in Rhinebeck, but later reinterred at an unknown location.