Hope Castle, Georgian castle in Castleblayney, Ireland.

Hope Castle is a three-story stone building in Castleblayney featuring five bays across its front and decorative ironwork details. Multiple wings extend from the central structure, creating an irregular footprint that grew as the building was expanded.

Lieutenant-General Andrew Blayney, 11th Baron Blayney, built the present house in the 1780s beside the older Elizabethan castle; it was redesigned in Georgian style by architect Robert Woodgate in 1799. In 1853 Cadwallader, 12th Baron Blayney, sold the estate to Henry Thomas Hope, whose family gave the house its current name. The Hopes left in 1916.

The castle displays how Georgian design elements were combined with Victorian modifications as different owners made their mark over time. These architectural layers tell the story of how the building was adapted for each new period of occupation.

The building is derelict after the November 2010 arson attack and is not open to visitors. The gate lodges, stables and bath houses survive, and the grounds border a forest and the lake known as Black Island. Access to the interior is unsafe.

The 1862 ironwork for the gate lodges, stables and bath houses was made by James and Alexander Shekleton, a father-and-son firm, for Anne Adèle Bichat, widow of Henry Thomas Hope. The stable yards were rebuilt slightly later, around 1865.