Blackman, 26, has joined Derby on a three-and-a-half year contract from fellow Sky Bet Championship side Reading for an undisclosed fee.
Capable of performing out wide or as a striker, Blackman is the club’s second signing of the January transfer window after the arrival of Abdoul Camara from French side Angers SCO on Monday.
The frontman has been in fine form in front of goal this season and has scored 13 times in 28 appearances in all competitions, as well having three assists to his name.
He is currently third in the Championship’s goalscoring charts this season with 11 in 25 league outings.
Blackman has attracted interest from various clubs but Derby have beaten off the strong competition to land his signature.
Head Coach Paul Clement said: “Nick Blackman has been in excellent form for Reading this season so we are delighted to bring one of the Championship’s leading goalscorers to the club.
“There has been a lot of interest in him so we’re naturally happy that he has chosen to join us.
“We’ve got a number of talented players in the attacking areas of our squad and Nick only enhances that.”
He added: “I know Nick from my short time at Blackburn Rovers in the 2011/12 season and look forward to working with again.”
Blackman began his professional career at Macclesfield Town, signing a professional contract in 2007 and making his debut at the end of the 2006/07 season at the age of 17.
He scored his first professional goal in 1-1 draw with Dagenham & Redbridge in the 2007/08 season and made ten further appearances that year, but his potential was catching the eye of the a number of sides up the football pyramid.
After a trial at then Premier League Blackburn Rovers he moved to Ewood Park in the 2009 January Transfer Window, before moving on loan to Blackpool for the rest of the season a few weeks later to gain more first-team experience.
He had a similar loan spell at Oldham Athletic in 2009/10 before enjoying two loan stints in the Scottish Premier League with Motherwell, where he impressively scored ten goals in 20 games, and Aberdeen.
He made his top flight debut at the start of the 2011/12 campaign as a substitute in a 2-1 home defeat to Wolverhampton Wanderers, as well as making two more appearances in the Capital One Cup.
Blackman moved to League One Sheffield United at the start of the 2012/13 season and scored 14 goals in 33 appearances before moving back to the Premier League with Reading in the January Transfer Window.
He was a regular face in their side as the Royals were relegated from the top flight and he also featured heavily in the 2013/14 and 2014/15 seasons back in the Championship, reaching the semi-finals of the FA Cup in the latter, before hitting an impressive run of form in the current campaign.