Is it allowed to work part-time during the Ireland study visa period and how many hours per week?

Yes, as an international student in Ireland, you can work part-time, up to 20 hours per week during term time and up to 40 hours per week during scheduled holidays. You must be enrolled in a full-time eligible course and have a PPS number before starting work. Be careful not to exceed the permitted hours to avoid risking your student visa status.