Thomas Aubrey Spring Rice, 3rd Baron Monteagle of Brandon CMG MVO (3 November 1883 – 11 October 1934) was an Anglo-Irish peer and British diplomat.

He held appointments in St Petersburg (1908-1910) and Washington DC (1910-1919), where he served alongside his relation, Sir Cecil Spring Rice, who was ambassador.

Spring Rice was sympathetic to the Irish Home Rule movement and, although he maintained the public façade of being a unionist, he was close to many people involved in nationalist politics.

Alongside his father, he helped to arrange the Irish Convention in 1917, using his personal connections to ensure that the interests of Sinn Féin were represented after the party leadership refused to attend.

Spring Rice did not marry, and was succeeded in the title by his uncle, Francis.