The 45-year-old Blaney began his professional playing career at Leinster in 1994 before joining Munster in 2000, where he spent five seasons with the province during which they were Heineken Cup finalists in 2002 and Celtic Cup winners in 2003.
After a playing career working with some of the best local and international coaches in Irish Rugby, he has spent the last 15 years coaching at Terenure College RFC following a transition to coaching in 2006 as player-coach and then assistant coach.
In his seven years as 'Nure head coach, he took them from Division 2A to the top flight, famously winning the Division 1B title in 2013/14 with 18 straight wins and reaching the Division 1A semi-finals in both 2015 and 2018. Having struggled over the first half of this season, Blaney's men won six of their last eight games to avoid relegation.
Speaking about the appointment, Blackrock's rugby manager Clinton Arblaster said: "We are thrilled to have a coach of James's calibre join the club. Over the last number of years, the club management have invested significantly in our teams and infrastructure and this appointment signals our continued intent to drive the performance rugby section of the club." Paying tribute to the departing Carroll, Blackrock director of rugby Michael Hearty added: "Mick has led our Premier Rugby and Academy agenda for the past two seasons, contributing significantly to a great crop of young talent being developed in the club. We would like to thank Mick for the huge amount of work he has put in and we wish him and Laura all the best for their next adventure in the US."