The Tories won 37 of 64 seats to claim a majority and wipe out Labour's 22-seat majority from 2013.
Labour picked up 24 seats this time around, the Liberal Democrats won three and UKIP finished with none.
Towns where seats turned from red to blue included Swadlincote, Matlock, Glossop, Buxton, Ripley, Belper and Ilkeston.
Turnout was 38%.
Election 2017: Full results from across England
Conservative leader Barry Lewis described the result as "brilliant".
"We didn't think at this point in the electoral cycle we'd be taking control of Derbyshire County Council," he said.
"We fought a really good campaign on local issues and I think that's really helped. We got our manifesto out early and really hit the doorsteps."
This was Labour's last stand - its last county council to be defended in England. And its defences have proven to be weak.
The Conservatives have won across the south and centre of the county - in places like Heanor, Ilkeston and Ripley.
They've also taken seats off the Lib Dems. And it was a bad night too for UKIP - their share of the vote in Derbyshire collapsed.
The Conservatives have taken control of Derbyshire County Council with a massive swing from Labour.