Sir Robert Nathan KCSI CIE (1868–1921) was a British intelligence official notable for his work against the Indian revolutionaries in Bengal, Britain and North America.

After retiring from the ICS in 1915, Nathan joined the MI5's section dealing with the Indian seditionist movement in Europe, called MI5(g), that was formed at the time headed by Vernon Kell.

[10] Nathan identified plans by Ghadar Party and the Berlin Committee to assassinate Lord Kitchener in 1915 through an associate of Har Dayal, Gobind Behari Lal.

[12] Nathan was also responsible for the plans made by British intelligence in late 1915 to assassinate Virendranath Chattopadhyaya through agent Donald Gullick.

Through March 1917, Nathan worked closely with William Wiseman, and negotiated with the US State Department the details of the case against the Indian conspirators.