Robert Millar may refer to:
- Robert Millar, now Philippa York (born 1958), Scottish cyclist
- Robert Millar (marketer) (1877–1960), Irish–Norwegian marketer
- Robert Millar (soccer) (1890–1967), soccer player and coach
- Robert Millar (rugby union) (1901–1981), Scotland international rugby union player
- Robert G. Millar (1925–2001), Christian Identity leader
- Robert McColl Millar (born 1956), Scottish linguist
- Robbie Millar (1967–2005), chef and restaurateur
- Robert Millar (1950-2024), former drummer for English rock band Supertramp
- Robert "Bob" Millar, former guitarist and vocalist for Australian rock band The Deakins