Cabu by the Lakes has been given the green light to build more holiday chalets at its Killykeen site.
The plans had been subject to an appeal by An Taisce.
The Killykeen Forest Park holiday village currently consists of 28 chalets and can accommodate 112 people, with associated communal relaxation and eating areas.
It opened to the public in the summer of 2020.
With works to redevelop an on-site stable and this development of 15 chalets, it would allow Cabu to host a total of 213 visitors.
The works require the removal of 45 trees, with the applicant committing to planting 1.2 hectares of replacement trees.
Last July, Cavan County Council approved the latest plans but it was appealed to An Bord Pleanala less than a month later.
In its appeal submission, An Taisce argued that it may impact the integrity of nearby European sites; that the plans are being brought forward in incremental applications and that it could jeopardize conservation efforts for Lough Oughter.
In making its decision to dismiss the appeal, An Bord Pleanala said it was a "modest" development at an existing holiday site and would not seriously impact or injure the visual amenities or conservation of Killykeen and Lough Oughter.
12 conditions were attached to the decision.