Sir Robert Shirley (c. 1581 - July 13, 1628) was an English traveller and adventurer, younger brother of Sir Anthony Shirley.

He went with his brother to Persia in 1598, remaining in that country when the latter returned to Europe in 1599. Having married a Circassian lady he stayed in Persia until 1608 when the Shah sent him on a diplomatic errand to James I and to other European princes; after visiting Cracow, Prague, Florence, Rome and Madrid, he reached England in 1611 and had an interview with the king.

In 1613 he returned to Persia, but in 1615 he came back to Europe and lived for some years in Madrid. His third journey to Persia was undertaken in 1627, but soon after reaching the country he died at Kazvin.

His elder brother Sir Thomas was also a noted adventurer.