John Alexander Dewar (February 7, 1863 – August 14, 1945) was a farmer and political figure on Prince Edward Island.
He represented 3rd Kings in the Legislative Assembly of Prince Edward Island from 1912 to 1917 as a Conservative.
Following several votes against his party in the 38th General Assembly, Dewar lost the Conservative nomination in his district.
He ran and won re-election as an Independent the 1919 election, but was unable to win in 1923.
This article about a Prince Edward Island politician is a stub.