One member of the Seanad received public donations of at least €12,000 last year.
Independent senator Rónán Mullen revealed the donations in his filings to the public ethics watchdog, SIPO.
Senator Mullen was one of the main opponents of the Protection of Life During Pregnancy Bill when it was passed last year.
Senator Mullen accounts for almost three-quarters of the €17,000 in donations received by TDs, Senators and MEPs last year.
Politicians are only required to reveal donations in excess of €600, and do not have to disclose any donations below that amount.
2013's total for donations is significantly higher than the €3,800 disclosed in 2012.
Only three other politicians - Socialist MEP Paul Murphy, Fine Gael junior minister Paschal Donohoe, and Fianna Fáíl justice spokesman Niall Collins - received donations high enough to warrant disclosure.