The 28-year-old joins Jim Goodwin’s squad from Eerste Divisie club ADO Den Haag to boost their attacking options for the 2024/25 Premiership season.
It comes as Dundee United are set to play city rivals Dundee in their first game of the new campaign on Sunday, August 4.
Van der Sande scored 13 times in 42 appearances in the Netherlands second tier last season.
He started his career with Den Bosch and had a spell at both FC Eindhoven and NAC Breda before moving to Den Haag in 2023.
The forward will be in the Dundee United squad for Friday night’s friendly against Luton Town at Tannadice.
United confirmed the signing, which is subject to international clearance, on Thursday.
Jim Goodwin said: “Jort’s arrival is an exciting one for the club.
“His goalscoring record in Dutch football speaks volumes about his pedigree, having been at the top end of the second tier’s scoring charts on numerous occasions throughout the past decade.
“Linking up with teammates whilst playing with his back to goal is also a pivotal strength of his game, one which will bring a different dynamic to our frontline and have a positive impact on the versatility of the unit as a whole.”
Van der Sande said: “This is a big club with a rich history, and I’m ready to make some more.
“I’m a tough player who likes to be in duels with defenders, create chances for my teammates and most importantly, score goals!
“Off the pitch, I also think this will be a really good fit for me – I love the country, the accent and the people, and that made this an even more attractive proposition.”
