154th Infantry Brigade was a formation of Britain's Territorial Force/Territorial Army that was part of 51st (Highland) Division in both World Wars.

The Volunteer Force of part-time military units formed in Great Britain after an invasion scare in 1859 had no higher organisation than the battalion until the Stanhope Memorandum of December 1888 proposed a comprehensive mobilisation scheme.

[13][14] Although the TF was intended as a home defence force and its members could not be compelled to serve outside the UK, units were invited to volunteer for overseas service and the majority did so.

[13] The following officers commanded 154th (3rd Highland) Brigade during the war:[13] The TF was reconstituted on 7 February 1920 and was reorganised as the Territorial Army (TA) the following year, with some units having merged.

[18] After the TA was mobilised on 1 September 1939 154 Brigade had the following composition:[19] The 51st (H) Division joined the British Expeditionary Force (BEF) in France, 154 Bde landing on 3 February 1940.

However, when the Phoney War ended with the German invasion of the Low Countries on 10 May, 51st (H) Division was detached and serving under French command on the Saar front.

[19][20][22] On return to the UK, 154 Bde HQ was used during June and July 1940 to collect together the dratols of 51st (H) Division that had escaped from France.

[19][18][20][23] The brigade was reconstituted as follows:[19] The 51st (Highland) Division sailed for Egypt on 16 June 1942 and 154 Bde was engaged in the following actions under its command during the war:[19] 1942 1943 154 Brigade landed on mainland Italy as part of Operation Baytown on 5 September, but after holding the beachhead for a few days it was recalled to Sicily, arriving back on 8 September.