The incidents, which are not believed to be connected, took place in the south city centre and in two areas of Dublin 15, according to The Irish Times.
One of the knife attacks occurred at 5.30pm after two groups of young people became involved in a fight near St Stephen’s Green.
A man in his late teens was taken to St James’ Hospital for treatment after he suffered a suspected stab wound.
His injuries are not understood to be life threatening.
Gardaí are also investigating incidents of a more minor nature which took place in the city centre on Friday and Saturday.
Separately, an investigation has been launched after a stabbing in Blanchardstown which occurred at 5pm on Saturday.
A man in his 30s was taken to hospital after he sustained knife wounds in the incident at Fortlawn Drive, Dublin 15.
“Investigations are ongoing,” a Garda spokeswoman said.
Half an hour earlier gardaí received reports of another stabbing in the Parslickstown Drive area of Dublin 15.
A man, aged in his 40s, was rushed to hospital with suspected stab wounds.
No arrests have been made to date but separate investigations have been launched into the three incidents.