As the Noble false widow spider Steatoda nobilis (Thorell 1875) continues to expand its range across Europe, Asia and the Americas, its potential as an invasive species has not yet been fully assessed. Latrodectinae spiders are remarkably adaptable and possess fast-acting neurotoxic venom that can cause neuromuscular paralysis in vertebrates and occasionally feed on small reptiles. We describe here a predation event by a mature female Steatoda nobilis on a juvenile Zootoca vivipara lizard in suburban Dublin. This is the first report of Steatoda nobilis preying on a vertebrate, and the first report of a terrestrial vertebrate organism falling prey to an arachnid in Ireland. Zootoca vivipara is a protected species in both the Republic of Ireland and Northern Ireland and may increasingly fall prey to Steatoda nobilis as urbanisation encroaches on lizard habitat. Therefore, Steatoda nobilis should be closely monitored outside of its original native range to assess its status as an invasive species.