It is hoped this will bring a range of benefits, including reassuring potential visitors and investors that it is well run and progressive, and unlocking funds from central government and the EU to help finance local initiatives.
Llangollen has become only the second Cittaslow town in Wales after Mold, and is only the sixth in the UK.
Cittaslow grew from the Slow Food Movement, another international scheme which links the pleasure of food with a commitment to community and the environment by promoting local, seasonal produce and reconnecting people with where their food comes from.
Spokesman and Llangollen town councillor Phil Thane said: “We are delighted to have won accreditation which is a tribute to the hard work put in by the bid group and of our town clerk Gareth Thomas.
“When the council or a voluntary body in Llangollen applies for a grant from Cardiff, London or Brussels being a Cittaslow town shows that we are well organised and run and should help us bring more investment into the town.
“One of our main aims is to involve as many people as possible in Cittaslow Llangollen, which is why we’ve set up a website to show you what were doing at www. cittaslow.llangollentowncouncil.co.uk. We are also on Facebook and Twitter.”