Sir Robert Dennis (died 1592) of Holcombe Burnell in Devon, was a Member of Parliament for Devon in 1555 and served as Sheriff of Devon.
Robert Dennis was the eldest son of Sir Thomas Denys (c. 1477 – 1561) of Holcombe Burnell,Sheriff of Devon nine times between 1507/8 to 1553/4 and Member of Parliament for Devon who acquired large estates in Devon at the Dissolution of the Monasteries. His mother (his father's second wife) was Elizabeth Donne, a daughter of Sir Angel Donne, an Alderman of London, by his wife Anne Hawarden (alias Hawardine), of Cheshire, and widow of Sir Thomas Murfyn,Lord Mayor of London.
Dennis married twice. His first marriage was some time before 4 April 1552 to Mary Blount, the second daughter of William Blount, 4th Baron Mountjoy, and first cousin to Lady Jane Grey, the Nine Day Queen of England. Their children were:
His second marriage, at some time before 12 October 1555, was to Margaret Godolphin, a daughter and co-heiress of Sir William Godolphin of Godolphin in Cornwall. By her he had three sons and five daughters including:
Their other children included Arthur; James; Elizabeth, who was the wife successively of John Stewer, Sir Thomas Acton and Gilbert Blackaller; Margaret; Jane, who married Sir ... Fowks; Phillipa (died 1655), who married William Drake (died 1625) of Wiscomb; and Mary, who died childless.
Dennis died in 1592 and according to W. G. Hoskins, the Easter Sepulchre monument in Holcombe Burnell church was used as his tomb.