Ajax may refer to:

• Ajax the Great, a Greek mythological hero, son of King Telamon and Periboea
• Ajax the Lesser, a Greek mythological hero, son of Oileus, the king of Locris
• Ajax (play), by the ancient Greek tragedian Sophocles, about Ajax the Great

• Ajax Duckman, in the animated television series Duckman
• Marvel Comics:
  • Ajax the Greater, another name for Ajak, one of the Eternals from Marvel Comics
  • Ajax the Lesser, another name for Arex, one of the Eternals from Marvel Comics
  • Ajax, a member of the Pantheon appearing in Marvel Comics
  • Ajax (Francis Freeman), a fictional supervillain first appearing in Deadpool #14
• Martian Manhunter, a DC Comics superhero called Ajax in Brazil and Portugal
• Ajax, a Call of Duty: Black Ops 4 operative
• Ajax, a Genshin Impact playable character; see Tartaglia

• A-Jax (band), a South Korean boy band
• Ajax (band), an electronic music band from New York City
• Ajax (opera), by the French composer Toussaint Bertin de la Doué
• DJ Ajax (1971–2013; born Adrian Thomas), an Australian electro mashup DJ
• Lisa Ajax (born 1998), Swedish singer
• "Ajax" (song), a song by Tante Leen, 1969
• Ajax Records, a former North American record company

• Ajax (painting), a painting by John Steuart Curry
• Ajax (Disney), a fictional company (the Disney equivalent of Looney Tunes' Acme Corporation)
• A-Jax (video game), a 1987 Konami arcade game

• Ajax (floppy disk controller), a floppy disk controller fitted to the Atari STE
• Ajax (programming), Asynchronous JavaScript and XML, a method used in web application development, and a software framework for it

• Ajax (federal electoral district), in the Durham Region of Ontario
• Ajax (provincial electoral district), in Ontario
• Ajax, Ontario, a town in the Greater Toronto Area

• Ajax, Louisiana, an unincorporated community
• Ajax, Missouri, a ghost town
• Ajax Peak, a summit near Telluride, Colorado
• Ajax, South Dakota, an unincorporated community
• Ajax, Utah, a ghost town
• Ajax, Virginia, an unincorporated community
• Ajax, West Virginia, an unincorporated community
• Aspen Mountain (Colorado), also known as Ajax Mountain

• Mount Ajax, part of the Admiralty Mountains, Victoria Land, Antarctic
• 1404 Ajax, an asteroid

• Ajax (missionary), Arian missionary who converted the Suevi to Christianity (c. 466)
• Ajax, pen name of Sidney William Jackson (1873–1946), Australian naturalist and ornithologist
• Ajax, nickname of Heinrich Bleichrodt (1909–1977), German World War II U-boat commander

• AFC Ajax, a football club in Amsterdam, Netherlands
• Ajax Cape Town F.C., a South African football club
• Ajax Futebol Clube, a Brazilian football club
• Ajax de Ouenzé, a Congolese football club
• FC Ajax Lasnamäe, an Estonian football club
• Ajax Orlando Prospects, American soccer team from Orlando, Florida, a.k.a. Ajax America
• Ajax America Women, American women's soccer team from California
• Aias Salamina F.C., a football club in Salamina, Greece
• Ajax Sportsman Combinatie, a cricket and football club in Leiden, Netherlands
• Rabat Ajax F.C., a Maltese football club
• Unión Ájax, a football club in Trujillo, Honduras
• V.V. Ajax, a Surinamese football club

• Aias Evosmou, a Greek sports club
• Ajax Kenitra, a Moroccan futsal (indoor football) club
• Ajax København, a Danish handball team
• Ajax (horse) (born 1901), a French Champion racehorse
• Ajax II (born 1934), an Australian Champion racehorse

• HMS Ajax, several ships of the Royal Navy
• USS Ajax, several ships of the US Navy
• General Dynamics Ajax, a family of armoured fighting vehicles for the British Army
• Operation Ajax, the 1953 Iranian coup d'état

• Ajax (1906 automobile), a Swiss automobile
• Ajax (1913 automobile), a French automobile by the American Briscoe brothers
• Ajax (1914 automobile), an American automobile by Ajax Motors Co. of Seattle, Washington
• Ajax (1921 automobile), an American prototype that was not produced
• Ajax (Nash Motors), an automobile brand of Nash Motors, 1925–1926
• Ajax (locomotive), several train locomotives
• Ajax (motorcycle), manufactured in England between 1923 and 1924
• Ajax (crane barge), a floating crane used to install the Panama Canal locks
• Ajax (ship), various ships
• Ajax GO Station, a train and bus station in Ajax, Ontario, Canada
• Ajax Motors Co., an American carmaker, manufacturer of the Ajax (1914 automobile)

• Ajax (cleaning product), a brand of household cleaning products
• AFC Ajax N.V., a sports company associated with AFC Ajax
• Kanichee Mine, Temagami, Ontario, also known as Ajax Mine
• Ajax High School, a public high school in Ajax, Ontario, Canada
• AJAX furnace, a type of open hearth furnace

• All pages with titles beginning with Ajax
• All pages with titles containing Ajax
• Nike Ajax, the world's first operational surface-to-air missile
• Ayaks (Ajax), a hypersonic waverider aircraft program started in the Soviet Union
• Ayaks (disambiguation) (Russian: Аякс, romanized: Ayaks, lit. 'Ajax')