Born in New Brunswick in 1785 as the eldest son of Christopher Robinson (an officer of the Queen's Rangers) and Esther Sayre (daughter of Rev. John Sayre). He had two brothers: William Benjamin Robinson (writer of the Robinson Treaties), and John Beverley Robinson (Then Attorney General of Upper Canada; and two sisters. The family settled first at Kingston in 1792 and then York in 1798. Peter fought during the War of 1812, where he commanded a rifle company at the capture of Detroit. He was elected to the Legislative Assembly of Upper Canada in 1817.
Known for leading a large contingent of immigrants from Cork Ireland to Central Ontario in the 1820s, he is considered one of the founding Fathers of Peterborough Ontario as part of the imperialist settling of land in that area. These Irish were in part emigrating because of the poor economy of Ireland at the time. The value of Irish goods was low, potato crops were meager (the Irish Potato Famine was still decades away however) and population in Ireland was increasing dramatically. There was a push on by Parliament to increase the number of men able to defend British North America from the United States. These Irish settlers would be useful in potential border disputes. Many Irish too wished to leave the Old Country due to recent changes in British law which seriously curtailed the rights of Irish Roman Catholics: they were banned from practicing their faith, as well as being refused the vote.
He died a bachelor in Toronto on July 8, 1838
Due to his contribution to the region, Trent University named its founding college after him.