Neale Richmond has been appointed Junior Minister at the Department of Enterprise.
The Dublin Rathdown TD replaces Damien English, who resigned earlier this week.
Richmond will have responsibility for Employment Affairs and Retail Business and the Department of Social Protection.
In appointing him Taoiseach Leo Varadkar said Richmond is an exceptionally capable politician who had been at the forefront of the debate around Brexit.
It also means every TD in the Dublin-Rathdown constituency now holds a Ministerial position.
Damien English was the second Junior Minister from this Government - and indeed the Department of Business, Enterprise and Innovation to step down because of details contained in articles published online by The Ditch.
The first was Robert Troy last summer.
