Siccar Point is a rocky promontory in the county of Berwickshire on the east coast of Scotland. It is famous in the history of geology for Hutton's Unconformity found in 1788, which James Hutton regarded as conclusive proof of his uniformitarian theory of geological development.
Siccar Point is now in the parish of Cockburnspath but was formerly in the parish of Old Cambus, from which the ancient parish church of St Helen's Chapel survives as a ruin about one kilometre to the west of the point. The church is built in a Romanesque style, in a mixture of Old Red Sandstone believed to have been quarried from the nearby Greenheugh Bay and of the greywacke rock also used in the drystane dyke forming the field boundaries. It is likely that the medieval village of Old Cambus was nearer to Siccar Point than the extant hamlet of Old Cambus.
Siccar Point is famous in the history of geology as a result of a boat trip in 1788 in which James Hutton, with James Hall and John Playfair, observed the angular unconformity which Hutton regarded as conclusive proof of his uniformitarian theory of geological development.