Gerry Davis made a number of changes before the match with qualification for the finals tournament already secured but Ireland secured their third win from three with Stephen Chambers' free-kick in the 70th minute.
Westport goalkeeper Gary Cunningham came in for skipper Brendan O'Connell for his first Regions Cup qualifying appearance whilst Glen Daly of Malahide United, Aaron Humphries of Kilbarrack United and Bonagee United's Jack Parke also came into the side with Luke Casey suspended.
Ireland had secured qualification thanks to victories over San Marino and an emphatic 4-0 win over Romania on Friday ahead of the final match against hosts Bulgaria today. Despite the changes, Ireland started confidently and Bulgaria struggled to break down the resolute Irish throughout.
Few chances in the first-half for either side but Ireland stepped up the pace of the game in the second-half and Killester Donnycarney's Chambers scored a fantastic free-kick 20 minutes from time which sealed the win. T
The Amateurs can now look forward to next Summer's finals at a European venue yet to be confirmed but on the displays in the group qualifier, Gerry Davis' group will be confident of their chances in 2023.
With the recent friendly matches against Northern Ireland and Wales included, Ireland have won seven matches in a row, conceding just one goal during this special run from the Ireland Amateur side.
Ireland manager Gerry Davis said: "This has been a tremendous effort on the part of the players who have been excellent all week. We've had brilliant support from the FAI and I'm delighted for the Technical Staff too who have put so much work in behind the scenes.
"We've very high standards and we have applied ourselves in a thoroughly professional manner and we're earned the right to sit at the top table of European Amateur football and we look forward to the challenges next Summer will bring."
Republic of Ireland: Gary Cunningham (GK); Jack Parke, Lee McColgan, Jack McMullan, Glen Daly, Aaron Humphries (AJ O'Connor 63), Stephen Chambers, Nathan Broderick, Jimmy Carr, Sam Burgess (Deiric Hyland 81), Eoin Hayes (Eoin Murphy 51).
Referee: Vassillis Fotias (Greece)