Known as the Steatoda Nobilis in Latin, or false widow spider, it measures about an inch across and has a severe bite.
False widow spiders can be identified by their dark, shiny body and pale markings and by the cream band on their abdomen.
Environmentally they prefer outdoor buildings like sheds and garages, but they are known to take up residence in homes too.
But before your knees start knocking, Irish arachnologist Myles Nolan told the "Derek Mooney Show" this week that the spider doesn't pose a severe danger to the public.
'They don't leap at people from trees or anything like that. Obviously the severity of the bite depends on where it is and how much venom - a large dose of venom close to the heart could cause palpitations and maybe you should go the hospital. But a small bite to the tip of the finger would be no worse than a wasp sting.'
'There's a massive population all over Dublin now. Once you can tell them apart they're quite distinctive.'
According to the Irish Independent the spiders originally arrived in the UK from the Canary Islands more than 100 years ago, and since then have spread to Ireland.
Climate change has reportedly allowed their numbers to swell.
A bite from a false widow can cause a serious allergic reaction, but they are not as venomous as the black widow. The false widows only bite when they have been provoked and the pain of their bite is said to be similar to that of a bee sting.
Although the bite from a false widow spider is rarely fatal, it can cause a severe allergic reaction, which could necessitate medical treatment.
See a false widow spider eat its prey:
How to kill a false widow spider: