- William Sinclair, who died in 1527 without issue.
- George Sinclair, 4th Earl of Caithness, heir and successor.
- David Sinclair, a natural (illegitimate) son who was Bailie to the Bishop of Caithness. His elder brother George obtained a remission to imprison him in Castle Sinclair Girnigoe. David is also believed to have been the paternal ancestor of the noble Sinclair of Dun and Forss families.
|Peerage of Scotland|
| Earl of Caithness