Janet Smith may refer to:

• Janet Kennedy Smith (1902–?), Scottish-born Canadian murder victim in the Janet Smith case
• Janet Adam Smith (1905–1999), Scottish writer, editor, and literary journalist
• Janet Smith (Rhodesia) (1915–1994), wife of Ian Smith, Prime Minister of Rhodesia
• Janet Smith (judge) (born 1940), Lady Justice of Appeal of the Court of Appeal of England and Wales
• Janet E. Smith (born 1950), American professor of moral theology
• Janet L. Smith (born 1951), American scientist
• Janet Marie Smith (born 1957), American MLB executive, architect, and urban planner
• Janet Marilyn Smith (1966–1994), American woman killed in the 1994 Gresham cat hostage taking incident
• Janet Seymour-Smith (1930–1998), English translator and scholar
• Janet Smith (sprinter) (born 1968), British Olympic sprinter
• Janet Smith (runner) (born 1965), American long-distance runner, All-American for the NC State Wolfpack track and field team
• Janet Smith, fictional character in Two Pints of Lager and a Packet of Crisps