The signing marks a new record for a Championship signing, which was previously held by Mike Tresor's £15.4 million move to Burnley last summer.
Egeli came through the ranks at Eliteserien side Sandefjord before signing for Nordsjaelland in the summer of 2023. He then went on to play 42 games for them, scoring 11 goals.
The 19-year-old forward will wear the No. 8 shirt at Portman Road
“I’m really excited to have signed for this club,” he said after completing his move.
“This is a club with great history and great plans for the future, and this is something I really want to be a part of.
“As soon as I knew Ipswich were interested, I was excited to come, and I believe this club is the perfect place for me to progress in my career.
“I have had some great conversations with the Manager and now I can’t wait to get started, meet my teammates, and also the supporters.”
Egeli, who has one Norwegian cap to his name, will become Ipswich's fourth signing of the week, but he won't count towards their Championship squad limit as he is under the age of 21.
Egeli wasn't registered in time for tomorrow's game against Derby, but he will be in attendance at Portman Road.