The 28-year-old joined Widnes from Hull FC in 2012 and has since gone on to make 61 appearances in a Vikings shirt.
O'Carroll has played in every match for the club so far this season, helping Widnes to third in the Super League with six wins from nine games.
"It's an honour to sign for a club that has the belief and desire that Widnes does," O'Carroll told the club's official website.
"The decision was easy for me as I love coming to work every day with my best mates. We have real aspirations for this year and the upcoming years and I look forward to working hard to achieve those goals."
Vikings head coach Denis Betts added: "Eamon is a valuable member of the group and an outstanding front-rower. O'Carroll being in the team makes us a stronger outfit and to have him sign for another two years is an important acquisition for the club.
"Eamon is a genuine family man, loyal, committed and hard working and has so much more to give to the game after having a tough run with injuries over the years. With Eamon fit he is sure to make many more appearances this season and in the future."
O'Carroll is the second Widnes player to commit his future to the club this week after Joe Mellor signed a three-year deal on Wednesday.