And Connacht have also signed promising hooker Sean Cronin - the former Irish Under-21 joins from Munster.
Connacht CEO Gerry Kelly hopes that Shannon clubman Cronin can follow in the footsteps of current senior internationals Jerry Flannery, Eoin Reddan and Bernard Jackman, all of whom went on to make the Irish side after spells with Connacht.
"Connacht offers players of the calibre of Sean Cronin the opportunity to develop and we are delighted to have him on board," said Kelly.
The Connacht CEO said that the two-year contract extensions of Loughney (23), Morris (26) and Flavin (28) were also a big boost.
Meanwhile, hooker John Fogarty will be moving to Leinster at the end of the season after five years with Connacht, having originally joined from Munster.
"John has been a great player for Connacht over the past few years and we would like to wish him the best in his career with Leinster," Kelly added.