Coshma () is a historical barony in southeast County Limerick, Ireland.
Baronies were mainly cadastral rather than administrative units. They acquired modest local taxation and spending functions in the 19th century before being superseded by the Local Government (Ireland) Act 1898.
The UàFidgenti were the dominant Irish kingdom in the Coshma region. The UàConaill Gabhra (Hy Cnocnuil Gabhra) were in the area and were part of the Eóganachta. The àCinnfhaolaidh (O'Kinealy, O'Kenealy) were chiefs of Eoganacht Grian Guara which included Coshma and the barony of Smallcounty. Before the Norman conquest the àCleirchÃÂn (O'Clerkin, Clerk, Cleary) were in Coshma as Lords of the UàFidgenti and of Ui-Cairbre.
Coshma was known as a centre of Irish-language poetry, with the Maigue poets being nationally famous. Aindrias Mac Craith wrote of the area as , "Coshma of the berries," in his poem "Slán le Máigh" ('Farewell to the Maigue'). Mannix Joyce also wrote about the Coshma region and its literature.
Coshma is in the middle of the county, going along the River Maigue; the Irish name means "banks of the Maigue."
Settlements within the historical barony of Coshma include: