The 68-year-old singer died Tuesday.
The service will be held at 2 p.m. Monday at St. Mary's Church.
MacNeil's publicist says it hasn't been decided yet whether the funeral will be open to the public and media.
MacNeil died in hospital in nearby Sydney following complications from surgery after a recurring infection.
Her powerful voice explored genres from country, to folk, to gospel.
An unlikely star, MacNeil worked tirelessly over decades to gradually become a beloved fixture in Canadian culture, with her greatest success coming after she was in her 40s.
She was painfully shy and admitted to battling self-confidence issues, largely stemming from her weight. Yet she was a renowned live performer who sold out gigs around the world.