I'm delighted to join this Club, I cannot wait to get started.Sam Cosgrove
The striker joins the Club for an undisclosed fee from Scottish Premiership side Aberdeen and has agreed terms on a three-and-a-half-year contract that will run until June 2024.
Talking to BCFC.com, Cosgrove spoke of his excitement at joining Blues.
He said: "It feels really good to be here. As soon as the interest was there from Birmingham it was a no brainer from me and I'm really delighted to get it over the line.
"There's a big job for me to do here. I'm looking forward to playing in the Championship. I know how demanding it is but I wouldn't be here if I didn't think I was ready to take on the challenge. Short-term, it's helping the team. Long-term it's echoing that - being as successful as I can and helping this fantastic Club."
24-years-old, Cosgrove started his career at Wigan Athletic and experienced loan spells with Barrow AFC, Chorley and close to where he was born on Humberside with North Ferriby.
In August 2017 he signed for Carlisle United, before earning his move to the Granite City on deadline day the following January.
Under Derek McInnes, Cosgrove has found the net 47 times in 103 appearances for The Dons and in December 2018 was named Scottish Premiership player of the month.
In the campaign that followed Cosgrove found the net 23 times, including on six occasions during Aberdeen’s run to the Europa League third qualifying round.
Cosgrove is Aitor Karanka’s second signing of the January window after Rekeem Harper joined on loan until the end of the season from West Bromwich Albion and has been handed the number 16 shirt.
Welcome to Blues, Sam.