The 26-year-old arrives for an initial £8.5m, with a further £2.5m available in add-ons, becoming Town's second Dutch goalkeeper recruit of the summer following the earlier £3.4m arrival of Kayne van Oevelen, and their sixth new signing overall.
Standing at 6ft 9in, Scherpen has previously played in England with Brighton & Hove Albion and has top-level experience in the Netherlands with Ajax and Vitesse Arnhem, and in Austria with Sturm Graz, having reached the Champions League group stage in each of the last two seasons. He has been capped up to Under-21 level by the Netherlands and also received a senior call-up earlier in his career.
"This is a very proud moment for me. This is a great opportunity for me to show my qualities and test myself in the best league in the world, so I'm really looking forward to making memories together," Scherpen said.
"I've had great conversations and everything here has been really positive, so it's made me very excited to join Ipswich Town. I'm looking forward to meeting my teammates and can't wait to meet the fans and get started."
Ipswich Town manager Gary O'Neil welcomed the goalkeeper's pedigree across multiple leagues.
"Kjell is a strong addition to our goalkeeping unit and we're delighted to have him with us," O'Neil said. "He has experienced playing at the top level in different countries, as well as in European competitions, and is excited to now have the opportunity to test himself in the Premier League.
"We're looking forward to him joining up with the rest of the squad and begin to prepare for the season with us."
Born in Emmen, Scherpen began his career at his hometown club before joining Ajax in 2019, where he won the Eredivisie and KNVB Cup during two seasons in Amsterdam. He moved to England with Brighton in 2021, making his debut in an FA Cup win over West Bromwich Albion before loan spells at Oostende, Vitesse and, twice, Sturm Graz, helping the Austrian club to back-to-back league titles.
A permanent switch to Union Saint-Gilloise last summer yielded 43 appearances, 21 clean sheets and the Belgian Cup, form that ultimately convinced Ipswich to bring him back to English football as their new first-choice.