Robert Mills may refer to:
- Rob Mills (born 1982), Australian musician and television presenter
- Robert Mills (architect) (1781–1855), American architect
- Robert Mills (physicist) (1927–1999), American physicist
- Robert Mills (politician), American politician
- Robert P. Mills (1920–1986), American magazine editor
- Robert L. Mills (1916–2006), American president of Georgetown College
- Robert Mills (rower) (born 1957), Canadian Olympic rower
- Robert Mills (priest), Dean of Dunedin