While many mixed doubles tennis players have won at least one title in each of the four Majors, a career slam, only one mixed doubles team has won the coveted "Grand Slam", all four titles in a single calendar year, Margaret Court and Ken Fletcher in 1963. Margaret Court and Owen Davidson also won an individual "Grand Slam" with different partners.
List of Mixed Doubles Grand Slam tournament champions in tennis:
References
List of Grand Slam mixed doubles champions Wikipedia(Text) CC BY-SA