This courthouse was designed by Joseph Welland and built in 1829 with stone from the local mountain quarry at Eshnaglogh.  The building was rebuilt in 1986 following a fire.

A refurbishment project was completed in 2010.  The building now provides three modern courtrooms - two are jury courtrooms and the third serves as a family law court.  Externally, the building is restored to its original form with the removal of service blocks to the side. Local stone was sourced for repairs to the façade. The entrance foyer was remodeled and lined with Carlow limestone and significantly increased in size. A large glazed atrium roof-light illuminates the principle circulation area which is dominated by a main public staircase constructed in Irish oak. The courtrooms are lined with oak paneling.  

The new facilities also include universal accessibility for all court users, victim support rooms, holding cell areas for prisoners, improved jury facilities and also consultation rooms for legal practitioners.

Monaghan Courthouse is supported by Monaghan Court Office.