Rosenallis (historically Rossinallis, from Irish: Ros Fhionnghlaise, meaning 'wood of the clear stream')[2] is a village in north County Laois, Ireland.

[3] In the same graveyard are the remains of Roger Byrne, who was said to have weighed 52 stone and been Ireland's heaviest man when he died in March 1804.

[6] In his Topographical Dictionary of Ireland (1837), Samuel Lewis described the area: "In the Slieve Bloom Mountains are quarries of a soft white sandstone, which hardens when exposed to the air, and is susceptible of a high polish; it is in great demand throughout the country for chimney-pieces and hearth-stones; a coarser kind is used for flagging.

There is a large tract of bog in this district, affording an abundant supply of fuel.

Rosenallis GAA is the local Gaelic Athletic Association club.