Hei or HEI may refer to:
Hei is the debut album of the Norwegian child duo Marcus & Martinus, winners of the Norwegian Melodi Grand Prix Junior 2012. The album released on Sony Music Entertainment on 23 February 2015 and was successful, peaking at number 2 on the Norwegian VG-lista official albums chart.
A special follow-up album was released nine months later on 6 November 2015 also on Sony including additional tracks. The special edition was titled Hei – Fan-Spesial.