The 25-year-old Healy has agreed a new three-year contract until the end of the 2015/16 season, while Ross has agreed a two-year deal until the end of the 2014/15 season.
Cork-born Ross represented both Munster and Ireland at underage levels before moving to English Premiership club Harlequins.
He agreed a move back to Ireland and Leinster for the beginning of the 2009/10 season and has gone on to make 80 appearances for the province.
He made his debut for Ireland in June 2009 against Canada and has won 24 caps since then, appearing in the Rugby World Cup in 2011.
Healy was a also an underage representative for both Leinster and Ireland and made his debut for his home province as far back as May 2007 - only two months after winning Ireland's first ever Under-20 Grand Slam.
In that time he has managed to make 109 appearances for Leinster and also won the first of 35 caps for Ireland against Australia in 2009.
IRFU Chief Executive Philip Browne said: "It is a very strong sign for Irish rugby to have such important players to both the Leinster and Ireland teams committing their futures to remain playing here.
"The market place for players continues to be a competitive one, but the IRFU and the provinces will continue to work to retain the best players in Ireland."
Mike Ross commented: "The last four years have been a great experience for me from winning my first cap for Ireland and playing in the Rugby World Cup to appearing in two Heineken Cup finals.
"Those are great memories and achievements in my career and so I'm delighted to have a new contract agreed to get the chance to hopefully continue that."
Cian Healy said: "The whole experience of playing for Leinster is something that I wanted to keep with me and also possibly winning more silverware as well.
"I still feel there is plenty more left in the tank for the province and there is a great group of players there and great support, so I'm really happy to have agreed a new contract to stay here in Ireland."
Leinster head coach Joe Schmidt added: "We're delighted that both Cian and Mike have each committed their futures to the province. It is a timely boost, not just for Leinster but also for Ireland ahead of the Six Nations.
"As a product of the Leinster system with Belvedere College at Schools level, then Clontarf at club level before graduating into the Academy system, Cian has proven himself at club and international levels over the last number of seasons.
"He has packed a lot of achievements into his career already with an Under-20 Grand Slam, Magners League and three Heineken Cup titles as well as 35 Ireland caps and 109 Leinster appearances.
"t is hard to believe he is just 25 years of age! We believe that Cian's best years are to come and we are pleased that he will do so in the colours of his home province."
The New Zealander continued: "Mike has been a mainstay of the Leinster squad and a consistent force in both the Leinster and Ireland front rows over the last few years.
"He has played a key role in our recent successes and his impressive form - in what is one of the most physically rigorous positions in the game - is a testament to his durability.
"Though Cork-born, Mike's strong performances over 80 career caps for Leinster have made him very popular with our supporters and they will be delighted that he will also remain in the squad for the coming seasons."