Retiring MEP Brian Crowley is entitled to a €200,000 payment on his departure.
The Fianna Fáil MEP, who is stepping back due to health concerns, has been a member of the European Parliament since 1994.
MEPs who do not get re-elected to parliament are entitled to a transition payment equivalent to their salary for one month per year served. For the Ireland South MEP, that leaves him in line for a payment of more than €210,000.
Meanwhile, Fine Gael's Brian Hayes is in line for a €52,000 windfall when he steps down from the parliament in May. The Dublin MEP has announced he is departing politics for the private sector.
The payment is one of the many allowances available to MEPs, including travel allowances, a €320 daily stipend when parliament sits, and a €4,513 monthly allowance to cover constituency costs.