The collapsed Portal Tomb of Tubbrid is located approximately 20.0 meters west of the River Pil, in a narrow valley, south of Grantstown, in the townland of Tubbrid (in Irish, Tiobraid) in County Kilkenny, Ireland. Portal Tombs, found in the British Isles, refer to megalithic structures where two equally tall, upright stones form the front of a chamber, covered by a partially massive capstone.

The east-west oriented Portal Tomb is situated in the middle of the remains of a roughly 10.0-meter diameter cairn, on a slope. The 4.5-meter-long, 2.6-meter-wide, and 1.4-meter-thick capstone has broken into two pieces. Its east side is supported by a single, relatively delicate 1.7-meter-high portal stone. The side stones and the endstone have collapsed inwards and are lying beneath the capstone.

Nearby, you can find the Ringfort of Barrabehy (in Irish, Barr Beithe).