A Scottish regiment is any regiment (or similar military unit) that at some time in its history has or had a name that referred to Scotland or some part, thereof, and adopted items of Scottish dress. These regiments were and are usually a product of the British Empire, either directly serving the United Kingdom, serving as colonial troops, or later as part of Commonwealth country military establishments. Their "Scottishness" is no longer necessarily due to recruitment in Scotland nor any proportion of members of Scottish ancestry. Traditionally, Scottish regiments cultivate a reputation of exceptional fierceness in combat and are often given romantic portrayals in popular media. Within Scotland, itself, regiments of the Scottish Lowlands usually never adopted as distinctively "Scottish" (specifically Scottish Highland) uniforms until the late Victorian Era and even then the kilt, that most distinctive aspect of the Highland soldier, was not adopted wholesale.
These generally predate the more widely known Highland regiments (see below). The senior Lowland regiment was the Royal Scots (the Royal Regiment) which dates from 1633. The Royal Scots Fusiliers and the King's Own Scottish Borderers were subsequently raised in 1678 and 1689 respectively. Throughout the 17th, 18th and most of the 19th centuries these Scottish regiments served widely and with distinction. They did not however differ significantly in appearance or public perception from the bulk of the line infantry of the British Army. In 1881 the introduction of the Cardwell system of reforms provided the opportunity to adopt a modified form of Scottish dress for the Lowland regiments. Comprising doublets and tartan trews this gave the Lowlanders a distinctive identity, separate from their English, Welsh, Irish and Highland counterparts. At the same time, the absence of kilts (except for pipers) and the substitution of Kilmarnock bonnets for feather bonnets prevented confusion between Lowlanders and their Highland counterparts. The Cameronians (Scottish Rifles) was created at the same time from the merging of two existing numbered regiments.