Background
He was born in Saint-Ouens, Manitoba and became a farmer and implement agent.
He was born in Saint-Ouens, Manitoba and became a farmer and implement agent.
Sinnott attended school in Saint-Ouens, then studied at Manitoba Agricultural College.
From 1936 to 1944 and again from 1950 to 1951, Sinnott served as reeve of Brokenhead, Manitoba. He was first elected to Parliament at the Springfield riding in the 1945 general election then re-elected for a second term in 1949. He opposed the government on a number of measures.
In the 1953 election, Sinnott ran as an Independent Liberal candidate and was defeated by Anton Weselak of the Liberal party.
In 1952, Sinnott voted for the creation of a pension for Members of Parliament of $3,000 per year if the Member of Parliament has served in parliament for at least 17 years. He then reversed his previous position and led a fight in the House of Commons against the creation of pensions for Members of Parliament and introduced a bill to make Member of Parliament salaries fully taxable.