The Shelbourne Ultimatum is a 2012 novel by Irish journalist and author Paul Howard and the twelfth in the Ross O'Carroll-Kelly series.

Ross survives the shooting depicted at the end of NAMA Mia!, but has to deal with Gardaí who don't believe his story.

[3] In The Irish Times, Patrick Freyne wrote that "in years to come, heavily footnoted editions of Paul Howard’s long-running series will be the textbooks on early 21st-century Ireland."

Well, Howard has chosen to consistently grapple with the little issues (decking, discount stores, bank shares, downsizing, failing businesses, Katie Holmes) in a manner that says more about contemporary Ireland than a whole Aosdána’s-worth of state-of-the-nation authors.

[7][8] It was the tenth-bestselling book in Ireland for 2012, and the second highest seller by an Irish author (behind Maeve Binchy's posthumous A Week in Winter).