Thomas or Tom Alexander may refer to:

• Thomas Alexander (military surgeon) (1812–1860), Scottish military surgeon, director general of the Army Medical Department
• Thomas C. Alexander (born 1956), American politician
• Thomas Cecil Alexander (1884–1968), founder of the Scouting movement in Malaysia
• Thomas G. Alexander (born 1935), American historian and academic
• Thomas A. Alexander (1800–1866), American politician
• Tom Alexander (actor) (born 1963), American writer, broadcaster, composer, and voice actor
• Tom Alexander (swimmer) (born 1958), Canadian swimmer.
• Tom Alexander (businessman) (born 1959), British businessman
• Tom Alexander (1934–2020), Scottish musician (The Alexander Brothers)