Blais is a surname, and may refer to:
- André-Albert Blais (1842–1919), Canadian Roman Catholic priest and Bishop of Rimouski
- Aristide Blais (1875–1964), Canadian physician and senator
- Chris Blais (born 1981), American rally racing rider
- Clifford Blais (born ca. 1956), Canadian family physician
- Dean Blais, American ice hockey coach
- Emmanuelle Blais (born 1987), Canadian ice hockey player
- François Blais (1875–1949), Canadian politician
- Greg Blais (born 1980), Canadian ice hockey player
- Isabelle Blais (born 1975), Canadian actress and singer
- Jean-Jacques Blais (born 1940), former Canadian politician
- Jean-Pierre Blais, Canadian public servant
- Jon Blais (1971–2007), American triathlete
- Louis Blais (1755–1838), Canadian farmer and political figure
- Louis-Henri Blais (1827–1899), Quebec lawyer and political figure
- Madeleine Blais, American journalist, author and professor
- Marguerite Blais (born 1950), Quebec politician, journalist and radio host
- Marie-Claire Blais (born 1939), Canadian author and playwright
- Marie-Claude Blais, Canadian politician
- Mathieu Blais (born 1983), French footballer
- Mimi Blais, French Canadian pianist, composer and comedian
- Narcisse Blais (1812–1888), Quebec farmer and political figure
- Peter Blais, Canadian actor
- Pierre Blais (born 1948), Canadian jurist and politician
- Raynald Blais (born 1954), Canadian politician
- Richard Blais (born 1972), American chef
- Roger Blais (1926–2009), Canadian geological engineer and academic
- Stephen Blais (born 1980), Ottawa City Council member
- Suzanne Blais-Grenier, former Canadian politician
- Yves Blais (1931–1998), politician in the Canadian province of Quebec