In Scotland, after the 1715 defeat of the clans, one of the highland leaders, Rob Roy MacGregor escapes, has lots of adventures, gets married, and eventually becomes enough of a nuisance to George I to be outlawed, and hunted by the English. Rob Roy leads his McGregor clansmen against King George I's forces commanded by the Scottish Duke of Argyll. While determined to establish order in the Highlands, Argyll is sympathetic to "the bonny blue bonnets" whom he is fighting, even refusing to unleash German mercenaries against them. A final charge by royal dragoons scatters the clansmen but honour appears satisfied and Rob Roy returns to his village to wed his beloved Helen. The wedding celebrations are interrupted by fencibles - the private army of the Duke of Montrose who has been appointed as the King's Secretary of State for Scotland and who lacks Argyll's regard for the highlanders. All clans involved in the rising of 1715 are pardoned except for the McGregors.
Rob Roy is arrested and the Clan McGregor is deprived of the right to use its name. Rob Roy escapes, leaping a waterfall and subsequently leads McGregor opposition to the increasingly repressive regime imposed by Montrose through his agent Killearn. A fort is stormed by the clan and its garrison of English soldiers taken prisoner.
The Duke of Argyll goes to King George to plead the case for leniency for the Clan McGregor, who have been forced into rebellion. At a crucial point Rob Roy appears at the royal court, heralded by a piper. Rob Roy's self-evident qualities quickly convince the king to pardon him and his clan. After an exchange of compliments: "Rob Roy - you are a great rogue"; "and you sire are a great king", the McGregor returns to his people and his wife.
- Richard Todd as Rob Roy MacGregor
- Glynis Johns as Helen Mary MacPherson MacGregor
- James Robertson Justice as Duke Campbell, of Argyll
- Michael Gough as Duke of Montrose
- Finlay Currie as Hamish MacPherson
- Jean Taylor Smith as Lady Margaret Campbell MacGregor, of Glengyll
- Geoffrey Keen as Killearn
- Archie Duncan as Dugal MacGregor
- Russell Waters as Hugh MacGregor
- Marjorie Fielding as Maggie MacPherson
- Eric Pohlmann as King George I
- Ina De La Haye as Countess von Pahlen
- Michael Goodliffe as Robert Walpole
- Martin Boddey as General Cadogan
- Ewen Solon as Maj. Gen. Wightman
Richard Todd related in his autobiography that the extras were soldiers of the Argyll and Sutherland Highlanders who had just returned from the Korean War. Todd said as well as providing thrilling battle scenes for the viewers, the soldiers used the opportunity to enthusiastically get back at their non-commissioned officers. Todd also sheepishly admitted that his first scene leading a charge led to an injury when he stepped in a rabbit hole.
- ↑ Todd, Richard Caught in the Act Hutchinson 1986