Ajax can refer to:
Mythology and literature
Ajax (mythology), also known as Telamonian Ajax or Ajax the Great, a Greek hero and legendary king of Salamis who plays an important role in Homer's Iliad
Ajax the Lesser, or Oilean Ajax, a Greek hero and legendary king of Locris who appears in Homer's Iliad
Ajax (Sophocles), a tragedy by the Greek playwright Sophocles, whose main character is Telamonian Ajax
Sport
AFC Ajax, an association football club from Amsterdam, the Netherlands
Ajax America, also known as Ajax Orlando, an American soccer team from Orlando, Florida
Ajax Cape Town, a South African association football club
Ajax Kenitra, a Moroccan futsal (indoor football) club
Ajax (horse), a champion Australian racehorse of the 1930s
Ajax Lasnamäe, an Estonian football club
Rabat Ajax, a Maltese football club
Ajax Skoteras, a Greek football team from "Skotera" village in Aitoloakarnania, Greece
Ajax Sportman Combinatie (ASC), a cricket and football club in Leiden, The Netherlands
Aias Salaminas, a football club based in Salamina, Greece birthplace of Ajax the Telamonian.
Vehicles
Ajax (1906 automobile), Aigner, Switzerland
Ajax (1913 automobile), Briscoe, France
Ajax (1921 automobile), prototype, U.S.
Ajax (automobile), Nash Motors, 1925–1926, U.S.
HMS Ajax, several ships of the Royal Navy
USS Ajax, several ships of the United States
Ajax (1860 locomotive), one of the eight South Devon Railway Dido class steam locomotives, in service 1860-1884
Ajax (1927 locomotive), a LMS Royal Scot Class express locomotive, in service 1927-1962
Fiction
Ajax (Disney), a fictional company (the Disney equivalent of Looney Tunes' Acme Corporation).
Ajax Duckman, a character in the animated television series Duckman
Martian Manhunter, a comic superhero called Ajax in Brazil and Portugal.
Ajax (comics), the name of two fictional characters from the Marvel Universe.
Ajak, another Marvel Comics character, a member of the Eternals, sometimes known as Ajax the Greater.
Music
Ajax (band), from New York City
Ajax WidowMaker, lead rapper of the Horrorcore group Rye Town's Creatures
Ajax Records (Chicago), a record label
Ajax Records (Quebec), a record label active in the 1920s
AjaX, keyboardist in The Pop Culture Suicides
Places
Ajax, Ontario, Canada
Aspen Mountain (Colorado), also known as Ajax Mountain
Information Technology
Ajax (programming) (Asynchronous JavaScript and XML), a technique used in web application development 
Ajax framework, a framework for the Ajax technology
Other uses
Ajax, a 1987 shoot 'em up arcade game released by Konami
Ajax cleanser, a household cleaner
Operation Ajax, a 1953 Anglo-American covert operation to overthrow the government of Iran
Apatosaurus ajax, the type species of the Apatosaurus genus of sauropod dinosaurs
Nike Ajax, an American anti-aircraft missile system
1404 Ajax, an asteroid
Ajax, an early flush toilet invented in England in 1596
Ajax, a member of The Warriors gang.
