Geoffrey George Gordon FitzClarence, 3rd Earl of Munster, DSO (18 July 1859 – 2 February 1902), known as Lord Tewkesbury 1870–1901, was a British peer, and the great-grandson of King William IV by his mistress Dorothea Jordan.

After his retirement he joined the part-time 3rd (Militia) Battalion, Royal Scots (Lothian Regiment) as a captain on 25 March 1896, and after some years' service in command of a company was promoted to the honorary rank of major.

The battalion was embodied in December 1899 to serve in the Second Boer War, and in early March 1900 left Queenstown on the SS Oriental for South Africa.

It was during his last military engagement in South Africa that Lord Tewkesbury received notice of his father's death and his own succession to the Munster earldom and other titles.

He never returned to the United Kingdom, dying in South Africa at the age of 42 from an accident at Lace Mines, just nine months after becoming 3rd Earl of Munster.