Ballyda (Irish: Baile Dháith) is a small townland in the civil parish of Danesfort in County Kilkenny, Ireland. The townland has an area of approximately 1.4 square kilometres (0.5 sq mi), and had a population of 70 people as of the 2011 census.

Evidence of ancient settlement within Ballyda townland includes a number of ring ditch and enclosure sites.

There is also a holy well site in the townland. This well, known as Lady's Well (Irish: Tobar Mhuire), is included in the Record of Monuments and Places as record number "KK023-075----". As of the late 20th century, a pattern was still celebrated at this well on 15 August each year, to mark the Feast of the Assumption of Mary. Several folkloric tales about Lady's Well are recorded in the Dúchas.ie "Schools' Collection". These include a number of stories which refer to apparitions of the Virgin Mary at the well. Several stories reflect common themes in the folklore of holy wells generally, such as that water collected from the well will not boil or that stones in the well are spotted with blood. The origin of the blood at Lady's Well is given as coming from a priest who was killed there by soldiers while saying mass. In one account, the leaves of nearby hawthorn bushes are also covered in spots of blood. One account tells of a woman whose eyes were cured after bathing her eyes in the well's water.

• List of townlands in County Kilkenny