The tower house dates back to at least 1640, when Richard Talbot owned 312 acres here that included, according to the Civil Survey of 1654-6, ‘one castle, one stone house and two mills’. By the nineteenth century, ownership had transferred to the Osborne family, and remarkably, the castle remains occupied today.

The castle itself is a rectangular tower house featuring distinctive architectural elements typical of its era. A barrel vault runs northwest to southeast through the ground floor, whilst projecting rectangular corner towers mark each corner of the structure; the southern tower contains a spiral staircase. The first floor is now an open space punctuated by Georgian-style windows on three walls, though the corner towers at this level have fallen out of use. Moving upward, the second and third floors are similarly empty but retain their original fireplaces on the southwest wall.

The building is topped with a hip roof, and steps lead up to what were once lookout points over the corner towers, though the crenellations that would have originally crowned these defensive positions have not survived. Despite centuries of modification and partial disuse, Dardistown Castle remains a substantial reminder of the fortified residences that once dotted the Irish landscape, blending defensive architecture with domestic needs in a way that allowed families like the Talbots and later the Osbornes to maintain their holdings through turbulent times.