Baltersan Castle is a ruined L-plan tower house located near Maybole, South Ayrshire, Scotland.

[2] The site was originally occupied by Baltersan House, owned by Egidia Blair, Lady Row, who died in 1530.

The inscription above the door tell us that the existing tower-house was built on the site in 1584,[4] the work of John Kennedy of Pennyglen (near Maybole) and Margaret Cathcart, his spouse.

[7] The castle was featured in an episode of Dragons' Den in 2005 in which the owner presented his restoration plans and time share financing strategy.

It has a vaulted ground floor and ashlar turrets on the northwestern and southeastern angles that are provided with gun loops.