Major-General Sir Donald Jay McMullen KBE CB DSO (27 July 1891 – 12 November 1967) was a British Army officer of the Royal Engineers who served in both of the World Wars.

A 1911 graduate of the Royal Military Academy, Woolwich, McMullen participated in the Gallipoli, Salonika and Sinai and Palestine campaigns of the First World War.

After the war he served with the British Control Commission for Germany as the Deputy Chief of the Transport Division until his retirement from the Army in 1948.

His father served in the Royal Flying Corps during the First World War,[2] for which he was made a Member of the Order of the British Empire in the 1919 New Year Honours.

In early 1915 he was assigned to the 117th (Railway) Company and sent to the Greek island of Mudros, which had been selected as an advanced base supporting the Gallipoli campaign.

He conducted exercises on railway and port operations, and taught the basics of military movement control to Staff College cadets.

[13] McMullen returned to the Middle East on 1 January 1936 as Assistant Director of Transportation, Egypt, Palestine and Trans-Jordan, with the local rank of colonel.

On the outbreak of the Second World War in September 1939, McMullen was appointed the Director General of Transportation of the British Expeditionary Force (BEF), with the rank of brigadier.

[19] Railway operations continued with aplomb in the chaos of the Battle of France, and the SNCF lost cohesion only after the German Army overran its headquarters.

[22] His citation, written by Major General Wilfrid Gordon Lindsell, read: He has shown marked ability, great driving power and complete self-sacrifice in developing from the outset the Transportation Services of the British Expeditionary Force.

Ports in Libya were rehabilitated to support the advance of the British Eighth Army from El Alamein to Tunis.

[2] In September 1946, McMullen joined the British Control Commission for Germany as the Deputy Chief of the Transport Division, a position he held until his retirement from the Army on 11 July 1948.