I wish to travel to Ireland in the next few weeks. As a convicted felon (possession of child pornography), will I have any problems gaining entry to Ireland?

Very likely, normally this type of info is not listed on visa and embassy web sites. You can contact the Dept of state for more information.

A visa is not required for stays less than 90 days, although at entry they may restrict how long you can stay. Proof of purpose of the trip is required at entry.