Thomas or Tom Williamson may refer to:

• Tom Williamson, Baron Williamson (1897–1983), British trade union leader and Member of Parliament
• Tom Williamson (English footballer) (born 1984), English footballer
• Tom Williamson (Australian footballer) (born 1998), Australian footballer
• Thomas Williamson (soccer) (born 1999), American soccer player
• Tom Williamson (Scottish footballer) (1901–1988), Scottish footballer
• Thomas Williamson (Australian politician) (1853–1921), New South Wales politician
• Tom Williamson (golfer) (1880–1950), English professional golfer
• Thomas Smith Williamson (1800–1879), American physician and missionary
• Tom Williamson (actor) (born 1990), American actor
• Thomas Wilson Williamson (1887–1974), American architect
• Thomas Williamson (surgeon) (1815–1885), Scottish surgeon and medical officer of health
• Thomas Andrew Williamson, American serial killer