I was thinking about this recently and have discussed it with a few friends and we can't think of anyone who has one every trophy available to a League of Ireland player currently.
League
FAI Cup
Setanta Cup
League Cup
First Division
There are lots of players with all bar one, players without the first Division or Setanta Cup for example.
I posted this on the City forum and we think we may have an answer in Jason Byrne. Can anyone confirm?
We're thinking if anyone has done it they would have needed to move around a lot. Derry and Sligo haven't won the league recently enough most likely and haven't won a Setanta, Bohs have no first Division, City have no League Cup in recent years, Shamrock have no domestic cups.
Most likely there have been players who have done something similar in previous years pre Setanta though