In the British Army and Royal Marines, company/battery/squadron sergeant major is an appointment for a WO2 and regimental sergeant major is a WO1 appointment.

Due to differences in nomenclature between Regiments and Corps sergeant majors' titles do vary; Squadron sergeant major and battery sergeant major for instance would be found in the cavalry and Royal Artillery respectively, and in the REME there are the appointments of artificer sergeant major.

Sergeant major instructor is an appointment held by warrant officers class 1 in the Small Arms School Corps and the Army Physical Training Corps and by some WO1s in the Royal Engineers. It is also an appointment held by some of the civilian adult instructors in the Army Cadet Force.

A machinist sergeant-major is a specialist most often found in the Corps of Royal Engineers or the Royal Army Service Corps, and was the title of one of the major characters in the book and the film based on it, Ice Cold in Alex.

For the use of "sergeant major" as a form of address, see the articles on regimental and company sergeant majors, and that on staff sergeants.

The posts of regimental and squadron corporal major are the Household Cavalry's equivalent of sergeant majors, as the Household Cavalry traditionally does not have ranks named sergeant. The Rifles use the spelling "serjeant major".