Janja is a town in Bijeljina, Bosnia and Herzegovina. Janja may also refer to:

• Janja Garnbret (born 1999), a Slovenian professional rock climber
• Janja Kantakouzenos (d. 1477), a medieval nobleman
• Janja Lalich (born 1945), an American sociologist and writer
• Janja Vidmar (born 1962), a Slovenian author and screenwriter
• Rosângela Lula da Silva (born 1966), a Brazilian sociologist and First Lady of Brazil

• Janja Monastery, a Serbian Orthodox monastery
• Janja, the antagonist hyena character from The Lion Guard television series