Aghavoher (from Irish Achadh an Mhothair, meaning 'field of the trees or mound') is small a townland in the civil parish of Tomregan, County Cavan, Ireland.

It is approximately 0.9 square kilometres (0.35 sq mi) in area and lies in the former barony of Loughtee Lower.

Its chief geographical features are Aghavoher Lough and the Rag River on its northern boundary and a small hill which rises to 306 feet above sea level.

The Tithe Applotment Books for 1827 list the following tithepayers in the townland: Profet, McKiernan, Stevens, Lee, Murrey, Berry, Patterson.

Patterson grants to Denham the lands of Aghavoher (Aughavoher) known by the name Sandybrook, barony of Lower Loughtee, County Cavan, by virtue of lease now held by.

Lands granted in order to indemnify Rogers against the payment of several legacies and annuities outlined in the will of Alexander Patterson, dated 28 February 1832.The Ordnance Survey Name Books for 1836 give the following description of the townland: Achadh a mothar, 'field of the cluster'.

[8][9] Griffith's Valuation of 1857 lists the landlords of the townland as Jones and Moore and the tenants as Berry, Winslow and Kellett.