James Boag I (– 9 November 1890) was the founder and proprietor of J. Boag & Sons, owner of the Boag's Brewery in Launceston, Tasmania, Australia.
Boag was born in Paisley, Renfrewshire, Scotland in 1822. He emigrated to Australia with his wife and four children in May 1853, on the ship Sea, and arrived in Tasmania in July of the same year aboard the Clarence after spending two months in Melbourne. Upon arriving in Tasmania he was engaged by J. D. Fawns of the Cornwall Brewery where he remained brewer and manager for 27 years. Once settled in Launceston, Tasmania he had 6 more children, including James Boag II.