The 33-year-old scored eight goals in 108 appearances for the Men in Green, and Ireland supporters reacted with disappointment at seeing a true great call time on his international career.
Here are some of the Tweets that caught our eye.
Ireland and Sunderland winger James McClean (@JMcC_23) pays credit to his idol: “I’m sad to see Damien Duff retire from international football, he was my idol growing up and to get to play with him was a huge honour! #legendduffer”
COYBIG (@COYBIG) hails a great Irish player: “So Damien Duff has joined Shay Given in retiring from international football. Great servant for us throughout the years. #COYBIG”
And Gary (@555BarcaBoy555) considers Duff to be one of the greatest footballers Ireland has produced: “Sad day as Damien Duff has retired from international football! One of the greatest players to wear an Irish jersey. @FAIreland”
Aodhán Ó Ríordáin (@AodhanORiordain) agrees: “Really sad to hear about Damien Duff’s retirement from international football. A genuine great. #damienduff”
Irishkop1892 (@Irishkop1892) says thanks: “Damien Duff has retired from international football for the Republic Of Ireland. He was a fantastic player for Ireland. Thanks Damo! #Duff”
Kevin McKenna (@kmckenna72) has a dig at former Ireland captain Roy Keane: “Thanks for giving your all Mr Damien Duff, loyal Irish servant. Have a piece of that Roy Keane you k**b!”
Oliver Walker (@locke24) reckons Duff was Ireland’s Ryan Giggs: “If the rumours are true then the best of luck to Damien Duff….he was our Ryan Giggs on the wing #thanksforthememories #Ireland”
Micheál (@Finical) is sad to see two greats go within a short period of time: “Sad to see Damien Duff join Shay Given retiring for Ireland. Both legends the two of them.”
Peter White (@pedro_blanco) reckons Richard Dunne and Robbie Keane will be next: “Damien Duff retired from international today…that’s Given and Duff gone..Robbie Keane and Richard Dunne next.”
Finally, Alan Cawley (@alancaw) heaps praise on a great player: “Damien Duff top professional and most of all a top person. We were very lucky to have him!!! #irishlegend”
MORE: Man United latest news
MORE: Arsenal latest news
MORE: Chelsea latest news
MORE: Liverpool latest news