The alarm was raised by the anxious owner after her dog, named Otis, chased some seagulls down over the cliff edge at Wicklow Head and disappeared.
The lifeboat — with helm Graham Fitzgerald and crew Ian Thompson and John Stapleton — was on scene eight minutes after launching and the crew began a sweep of caves and the shoreline at a location known as the Pond, near Wicklow Head lighthouse.
During the search the dog could be heard barking from a cave, so crew member Stapleton was put ashore near the opening and, with some persuading, the dog was coaxed out to climb back up the cliff and into the arms of his grateful owner.
Elsewhere, a young man was recovered from the River Corrib by members of the emergency services in Galway in the early hours of Friday morning following a major rescue operation involving the Galway RNLI lifeboat.
The man has got into difficulty in a canal beside the river around 3.30am, and during the rescue both the casualty and rescue personnel ended up entering the fast-flowing Corrib towards the Spanish Arch, where the casualty was recovered for transfer to Galway University Hospital.
Mike Swan, Galway RNLI lifeboat operations manager, said: “We would encourage all members of the public to respect the water at all times regardless of their activity.
“Be wary of all edges around the sea and watersides. Slips and falls happen in all locations.”