The seven candidates in last October's Presidential election spent a total of €2.3m on their campaigns.
Figures released by the Standards in Public Office Commission this evening show that the highest spender was Fine Gael's Gay Mitchell, who spent over €500,000.
In total, Mr Mitchell, who came fourth in the race to the Áras, spent €527,152 on his campaign.
Over €400,000 of Mr Mitchell's campaign was spent on posters, ads and other election material.
The Fine Gael MEP did not receive any donations and as he did not reach the required number of votes, he did not get any expenses back from the State.
The next biggest spender was Independent Mary Davis, who spent €414,041. She spent €93,000 on posters, which garnered some attention during the campaign.
Ms Davis received over €120,000 in donations from numerous individuals, including businessmen Dermot Desmond and Denis O'Brien, each of whom gave her €2,500.
However, because she came last in the race and did not reach the threshold, the State did not reimburse Ms Davis any of her expenses.
The winner of the election, now President Michael D Higgins, was the third biggest spender at €359,935. More than half of that expenditure went on posters and ads.
President Higgins also spent €4,114 on clothing for television appearances.
Most of the donations totalling €121,421 that he received came from elected members of the Labour Party, which he represented.
President Higgins reached the required threshold and received €200,000 back from the State.
Independent Senator David Norris was the next largest spender, although he came fifth in the election contest.
Mr Norris spent €331,974 on election expenses, a third of this going to pay campaign workers. He also received €17,929 in donations.
Senator Norris did not reach the required threshold and received no reimbursement from the State.
The SIPO report states that €30,008 of Mr Norris' listed expenses are in dispute, although it does not say what these expenses are for.
SIPO also states that a number of the expenses listed were deemed by it to not be election expenses in the context of the legislation.
However, SIPO says that because Mr Norris is not receiving any reimbursement from the State, because he did not receive the threshold, it is not pursuing the matter further with him.
The runner-up in the contest, Independent Sean Gallagher, was the fifth largest spender. He spent €323,318 in total.
Mr Gallagher made a point during the campaign of not using election posters. However, his filings show that he did spend over €200,000 on publicity and other election material.
He received donations of €28,759, including €2,500 from Independent Senator Fergal Quinn.
Mr Gallagher did reach the required threshold for reimbursement and so received €200,000 from the State.
Sinn Féin's Martin McGuinness spent the second lowest amount, although he finished third in the election contest. His expenses totalled €302,563.
Almost €3,000 of the €27,000 he spent on transport and travel was paid to Morgan Fuels, the company that owned by businessman Hugh Morgan.
Mr Morgan claimed during the campaign that he gave Sean Gallagher a cheque for a Fianna Fáil fundraiser in 2008, a claim which Mr Gallagher denied, but which had a pivotal effect on his campaign.
Tonight a Sinn Féin spokeswoman said Mr McGuinness' bus driver had a Morgan Fuels card, which she said were very common.
Mr McGuinness received €4,348 in donations, and was reimbursed €200,000 from the State after reaching the threshold.
The lowest spender was Dana Rosemary Scallon, who spent €59,591.
She received donations of €12,017 but did not receive any reimbursement from the State.
