Galway city centre's 14-day incidence rate of Covid-19 is nearly four times the national average.
The local electoral area's rate was 768 per 100,000 people on Monday - the highest in the country, but down 40 per cent on last week.
Limerick City East LEA is the next highest, at 608.
Padraic Toomey, the president of NUI Galway students union, says many of his area's cases are linked to college students.
Meanwhile in Mayo, the Claremorris LEA has a rate of 357; it was 295 in Swinford, 253 in Castlebar, 143 in Ballina, 131 in Westport and 64 in Belmullet, compared to the national average of 201 per 100,000.