Mason Dixon may refer to:
- Mason–Dixon line separating Delaware and Pennsylvania from Maryland, surveyed 1763--1767
- Charles Mason and Jeremiah Dixon, royal surveyors who developed the line
- Mason & Dixon, the 1997 novel by Thomas Pynchon featuring the surveyors as characters
- Mason-Dixon Polling & Research Inc., an independent polling firm
- Mason Dixon (artist), AKA Jameson Wallace, AKA Michael Crampton, Chicago academic and performer
- Mason Dixon (band), a country music band from the 1980s
- The opponent of the title character in Rocky Balboa