The name Roisin is a girl's name of Irish, Irish Gaelic origin meaning "little rose". Roisin and is often added to lists like Irish Baby Names for Girls and discussed in our forums with posts like "Girls Makeover - Two Middles".
From the experts:
No, the pronunciation--ro-SHEEN--isn't immediately obvious to the non-Gaelic viewer, but the sound of this shiny Irish version of Rose is pretty enough to make it worth considering. Very popular in its native Ireland, it is now at Number 34. Earlier generations Anglicized at as Rosaleen, but we stay stick to the original.
The name has been associated with a 16th-17th century poem called Roisin Dubh (Dark Little Rose), the eponymous heroine of which is usually regarded as a personification of Ireland.
Singer Sinead O'Connor has a daughter named Róisin.