Nadja is a feminine given name. Notable people with the name include:
Nadja Salerno-Sonnenberg, US violinist
Nadja Peulen, German bass guitarist for Coal Chamber
Nađa Higl, Serbian swimmer
Nadja Benaissa, German singer, member of No Angels
Nadja Käther, German track and field athlete
Nadja Sieger (*1967), Swiss comedian
Fictional characters:
Nadja, main character of the 1928 surrealist novel Nadja by André Breton
Nadja, the main character of the anime Ashita no Nadja
Nadja Nilsson, a fictional character in the Bert diaries