Philip was born to the aristocratic Pell family, at the manor house in what is now Pelham. The family had established itself in the area in 1654 when Thomas Pell bought nearly 10,000 acres (40 km²) from the Indians. Thomas' nephew John, named the entire tract Pelham Manor, and was viewed as the second lord of the manor. Philip was the third to have that name, and is sometimes known as Philip Pell, Jr. or Philip Pell, III.
Pell graduated from King's College (now Columbia University) in New York City in 1770. He read law, was admitted to the bar, and practiced in Westchester County and New York City. As the Revolutionary War began, he was a Lieutenant in the Westchester militia. His unit became part of the Continental Army in 1776 and he served until elected to the New York Assembly in 1779.
After three years in the Assembly, Pell rejoined the Continental Army, this time as a Colonel, and served as Judge Advocate General from 1781 until 1783. When the British finally left New York City in 1783 he was a member of George Washington's staff. He left the army shortly after, and Westchester County again elected him to the state Assembly where he served from 1784 to 1787. New York sent him as a delegate to the final session of the Continental Congress.
With the founding of the United States, Pell was active and vocal as an Anti-Federalist who opposed the ratification of the U.S. Constitution. In fact, Pell was the last member of the Continental Congress and was the only member present at its last "meeting" on March 2, 1789, two days before the Constitutional government took office; he oversaw the Congress's adjournment sine die. After the abolition of the Continental Congress, he withdrew from national and state politics. He did keep his local office as the surrogate for Westchester County until 1800.
Philip died at home in Pelham Manor in 1811 and is buried the St. Paul's Churchyard, in what is now part of the City of Mount Vernon, a suburb of New York City.