Hiberno English

Loan words from Irish (some of this may be folk etymology, especially the first one)
Dig – could be from Irish an dtuigeann tú, meaning “do you understand.”
Smithereens – Likely from the Irish smidiríní, meaning little fragments or bits.
Whiskey – Derived from the Irish uisce beatha, meaning “water of life.”
Galore – From go leor, meaning “plenty” or “abundance.”
Craic – From craic, meaning fun, entertainment, or enjoyable conversation.
Keening – From caoineadh; vocally lamenting the dead. 

Various turns of phrase and sayings
on the pig’s back
the life of Riley
you can’t fatten a pig on the day of the fair
the bird never flew on one wing
might as well be hung for a sheep as for a lamb
a horse of another colour
that beats Banagher
the old sod
down in the mouth
hurler on the ditch
a holy show
give out (yards)

Calques and Irish English constructions
Sure, it’ll be grand.
He’s after spilling it on me.
I have a thirst on me. 
There was not a bother on him.
You’ll get/catch your death of cold.
He let a roar out of him.
Is it reading you are? (This kind of construction can sound stage Irish if overdone and combined with other Irish-isms, e.g. “Is it after spilling the beer on me you are at all?”)
Is it yourself?
more is the pity
colleen (much loved of Irish Americans, not met that often in Ireland; the Irish for girl is cailín).
I wouldn’t put it past him.
I will yeah.
Is that right?

Miscellaneous
quare’n, e.g. it’s quare’n hot today. It is very hot today.
chisellers, childers
American wake
lashings of sth.
messages
rasher
gombeen
cog (vb.)
thick (can mean friendly with someone (thick as thieves) or stupid, but also angry, aggressive)
hooley
to have notions
banjaxed
ructions
idiot is often pronounced “eejit”
gouger
gurrier

Irish
rí rá agus ruaile buaile
flaithiúlach
plámás
crúibíní,
ciotóg
mar dhea
amadán

https://www.youtube.com/watch?v=LkcXjholnGk

https://www.youtube.com/watch?v=DyGpq4yKPG4