Heltne Nilsen started his professional career at
Norwegian Second Division side
IL Hødd. He started the
2012 Norwegian Football Cup final, playing the full match and scoring in the penalty shootout to help his team win its first cup title. In January 2014, Heltne Nilsen moved to
Vålerenga. He went to
SK Brann in July 2015. In July 2018, Heltne Nilsen moved to
Danish Superliga side
AC Horsens. He signed a five-year contract with the club, but was sold to Swedish club
IF Elfsborg in 2019. After a brief spell with Belgium's
Waasland-Beveren, Heltne Nilsen rejoined Brann for three years. In 2024, he reunited with former manager
Jimmy Thelin at the latter's new club,
Aberdeen, in the
Scottish Premiership. ==Career statistics==