Jack Coupar represented the electoral district of Colchester North, he was a member of the Progressive Conservative Party but and entered provincial politics in the 1984 election which elect members of the 54th House of Assembly.
He represented the electoral district of Colchester North in the Nova Scotia House of Assembly from 1984 to 1988. He was a member of the Progressive Conservative Party of Nova Scotia. Coupar entered provincial politics in the 1984 election, defeating Liberal incumbent Ed Lorraine by 160 votes in Colchester North. The 1984 Nova Scotia general election was held on November 6, 1984 to elect members of the 54th House of Assembly of the Province of Nova Scotia, Canada. 
