Robert Troy has resigned as a Minister of State.
He was facing pressure over his failure to fully declare his property interests in the Dáil register.
In a statement, Taoiseach Micheál Martin said he accepted his resignation "with regret".
A spokesperson for Mr Martin said: "The Minister clearly acknowledged that he made serious errors in relation to his declarations to the Register of Member’ Interests, and he sincerely apologised for this.
"Since his election to Dáil Éireann, his commitment to his constituents and dedication to his work has been beyond question."
While in a lengthy statement, Mr Troy said: "The last 10 days have been extremely difficult - but I would like to sincerely thank the Taoiseach, Tánaiste, and the large number of colleagues across the political divide who have shown their support and who continue to have trust in me.
"I would like to take this opportunity to assure members of the public once again that I have not tried to conceal anything.
"My biggest offense is my lack of due diligence.
"However, one issue in isolation is excusable but the number of errors now that are of my making directly or indirectly has led me to this decision."
He added that these were "genuine errors and human errors and were not intentional."