The nine new cubicles - which feature floor-to-ceiling doors - were added as part of an extension and redevelopment of the landmark costing £300,000.
Steward, John Solbe told Premier: "As a steward, [I believe] our mission for the cathedral is a mission of welcome.
"We respect all people who come to the cathedral and we welcome everybody; we want them to be comfortable."
Leaders say the lavatories have already been "well received" by members of the gay, lesbian, bisexual, transsexual, queer, intersex and asexual communities.
They have also been welcomed by fathers needing privacy when taking their children to the toilet and people who need the help of a carer, according the bosses.
Mr Soble added: "We put it [the idea] to the cathedral council - that was important - and there was a unanimous decision that this was the way to go."
Mr Soble explained that the new toilets were a more appropriate use of space, and a preferable alternative to needing to use portaloos for large events.
Dean of St Asaph Cathedral, the Very Rev Nigel Williams said: "St Asaph Cathedral is delighted to be leading the way in inclusive, accessible facilities for all visitors to the Cathedral.
"We hold a lot of large scale concerts and events so having as many cubicles as possible for both men and women was very important in the plans for our extension."
A new tea room and community meeting space are due to open later this year at the landmark, which is the oldest cathedral in Wales.
Click here to listen to Premier's Cara Bentley speaking with John Soble:
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