HJ may refer to:
Hjalmar Horace Greeley Schacht (22 January 1877 – 3 June 1970) was a German economist, banker, centre-right politician, and co-founder in 1918 of the German Democratic Party.
Hjalmar Peterson was a singer and comedian from Sweden, who achieved great popularity during the 1910s and 1920s.
Hjalmar "Hjallis" Johan Andersen (12 March 1923 – 27 March 2013) was a speed skater from Norway who won three gold medals at the 1952 Winter Olympic Games of Oslo, Norway.
HJ Bunko (HJ文庫) is a publishing label affiliated with the Japanese publishing company Hobby Japan. It was established in July 2006 and is a light novel label that is aimed at a young adult male readership.
Hjörtur Hermannsson (born 8 February 1995) is an Icelandic professional footballer who currently plays for Brøndby as a centre back.