HITC Sport understands the Blackburn ace is on his way to the iPro Stadium
The 27-year-old is out-of-contract at the end of the season and has turned an offer of a new deal to remain at Ewood Park.
Now, rather than lose him for nothing in the summer, Blackburn have accepted an offer from promotion hopefuls Derby as they look to bolster their squad for the final run-in.
Olsson, who was Blackburn's Player of the Year last season, followed his twin Martin to the club in 2012, joining from Halmstads in Sweden.
He has gone onto make over 100 appearances for the Lancashire outfit playing mainly in defence but also in midfield.
Now he is in talks with Derby and looks set to seal a move to the iPro Stadium in the coming days.
After splashing out for the likes of Abdoul Camara and Nick Blackman earlier this month, Derby had suggested they would not bring in any more new faces - but clearly Paul Clement feels additional new faces are required.