I have to tell you (I was just informed myself, as was my source, the good people at the OEDILF) of the International Limericks Competition. (And it is indeed “the” Limerick competition, based in Limerick, Ireland, as it is.)
Free to enter, up to three entries, must be original and in proper limerick form, with a cash prize of 1000 euros (if you are able to attend the final competition–that’s the bad news).
Deadline for entries is 30 July, so get busy!