The 28-year-old earned his first cap for Connacht in 2005 and has played a part in some of the biggest games in the westerners' history, including the 2010 Amlin Challenge Cup semi-final against Toulon and the historic first win in the Heineken Cup last season against Harlequins.
Last March, Loughney became one of the youngest members in the province's history to reach the milestone of 100 caps for Connacht.
As just reward for his consistently impressive performances for Connacht, he was called into the Ireland squad during the 2012 summer tour to New Zealand and earned his first international cap in the opening Test against the All Blacks.
The tighthead prop has appeared in six of Connacht's nine games so far this season and scored a second half try in their memorable 34-6 victory over Leinster in September.
Commenting on the new deal, Loughney said: "I'm thrilled to have officially committed to Connacht for another two years. There's nothing better than playing for your province and I couldn't imagine being anywhere else.
"As a team, we're achieving more and more each year and there's a real ambition amongst everyone to push on to the next level. I'm delighted to be a part of that upward curve."
Another of Connacht's most senior players, Brett Wilkinson, has also signed a contract extension that will see the loosehead prop stay at the Sportsground until the end of the 2014/15 season.
Wilkinson joined Connacht in 2006 from the University of Cape Town, after turning down the chance of Currie Cup rugby with Western Province.
Hailing from Grahamstown in the Eastern Cape of South Africa, he began playing rugby from the age of eight. It was his performances for his school which led to him being singled out for a scholarship to the University of Cape Town.
Wilkinson has made a huge impact at the Sportsground since his arrival nearly six years ago with his powerful scrummaging and excellent ball-carrying skills.
The Irish-qualified prop has featured in six of Connacht's nine games to date this season and is set to earn his 150th cap for the province on his next outing.
Wilkinson remarked: "Connacht has been my home for the last six years and I'm delighted to have re-signed for another two. It's a very exciting time for Connacht Rugby with the province competing in the Heineken Cup, PRO12 and British & Irish Cup this season.
"There's huge work being done both on and off the field and I'm really looking forward to contributing to that for at least another two years."
Commenting on the contract extensions, Connacht Rugby CEO Tom Sears said: "Both Ronan and Brett contribute enormously to the Connacht squad and I'm very pleased that they will continue to do so.
"Their signings are a great boost to the province as we continue our endeavours to build the strongest squad possible to compete in the Heineken Cup, RaboDirect PRO12 and British & Irish Cup."