Almost all stories of mass Irish immigration, before the 20th and 21st centuries, can be split distinctly into pre and post famine.
Pre-famine immigration from Ireland to Canada came mainly via shipping and industry. Although a small group of Ulster Presbyterians, also known as Scotch-Irish, emigrated and setup in Nova Scotia in the 1760s the first recorded Irish in Canada came as far back as 1536!
These hardy souls were Cork fishermen and they ended up settling in Newfoundland in a journey that set a precedent.
Over the course of the next 100 years various groups of seafaring Irish, mainly from counties Waterford and Wexford, made the journey across the Atlantic for jobs and opportunity. So much so that it’s estimated that up to 5% of New France (the name for the original Canadian colonies until 1763) was Irish in the 18th century.