On 31 October 1914 the battalion encountered German forces at Messines in Belgium, the first territorial unit to do so – a memorial stands on the site.

It was designated 97th (The London Scottish) Heavy Anti-Aircraft Regiment, RA and formed with HQ and two batteries (298 and 299) at Westminster.

[12][13][14] In March 1943 it left for North Africa where it joined British Eighth Army,[12][14][15] and served with it in the Allied invasion of Sicily and Italian Campaign.

[21] The London Scottish Cadet Corps, which was formed around 1902, had three companies, a pipe band and its own colours and was sponsored by the regiment.

[22] The corps evolved to become 235 Westminster Detachment (London Scottish Regiment), part of 23 Company Middlesex and North West London Army Cadet Force: it is based at the Rochester Row Army Reserve Centre in Westminster and alongside 102 (Bromley), and 95 (Southwark) detachments (Part of South East London Army Cadet Force) are the sole surviving cadet units maintaining the traditions of the regiment.

Outside of the United Kingdom, the band has had the opportunity to perform at many parades and military tattoos in countries such as Germany, Italy, Switzerland, Uzbekistan and Jamaica.