Alja is a Slovenian female given name. Notable people with this name include:
Alja Kozorog (born 1996), Slovenian slalom canoeist Alja Omladič (born 1983), Slovenian pop singer Alja Varagić, Slovenian handball player Alja Robinson Crook (1864–1930), American academic Alja Vrček (born 1993), Slovenian handball player