Clonlonan (Irish: Cluain Lonáin)[1] is a barony in south–west County Westmeath, Ireland.

The largest centre of population in the barony is the town of Moate.

The M6, a motorway forming part of the N6 Dublin to Galway national primary road and the N62 connecting the M6 to the M8.

In addition the R390, a regional road linking Athlone to Mullingar, the R444 linking the R357 at Shannonbridge, County Offaly with the N6 and the R446, part of the old N6 prior to the motorway, also feature.

A railway line carrying several of the national rail company Iarnród Éireann's intercity services also passes through the barony.