Morrow worked as the Head of Strength and Conditioning with Ulster Rugby from October 2003, being part of the management team that won the Celtic Cup in 2003/04 and the Magners League in 2005/06.
He left this role on 2008 to take up the position of IRFU High Performance Fitness Manager with responsibility for the fitness structures for underage elite players in Ireland.
He has provided his expertise to various GAA representative teams and has also worked with the Manchester City Academy players.
The IRFU Head of Fitness will be responsible for the continued development and implementation of the fitness strategy throughout all professional squads, working closely with the provincial and national fitness staff to ensure the highest level of physical conditioning and preparation for Irish teams.
Belfast native Morrow, who takes over the role from the retiring Dr. Liam Hennessy, said: "These are exciting times for Irish rugby and I am looking forward to working with the provincial and national team managements.
"The physical demands of rugby are constantly evolving, and we must ensure that we stay ahead of our competitors by being innovative in our approach.
"The structures in the IRFU and within the provincial teams have made significant advances over the years and these are due in no small part to the work of Dr. Liam Hennessy.
"I have worked with Liam for nearly a decade and my aim along with the provincial heads of fitness is to continue that progress."
IRFU Director of Rugby Eddie Wigglesworth said: "The role of strength and conditioning development is vital in the game and the appointment of Philip Morrow sees a certain level of continuity in the solid structures that the IRFU have in place.
"We are delighted to have somebody of his experience and expertise, who knows these structures so well, moving into this position and continuing the development of this area for Irish rugby."