Sir Robert Austen, 4th Baronet (6 October 1697 – 7 October 1743), was an English politician who sat in the House of Commons in two periods between 1728 and 1741.
Austen was the son of Sir Robert Austen, 3rd Baronet and his wife Elizabeth Stawell, daughter of George Stawell of Cothelstone Somerset. He succeeded to the title of 4th Baronet Austen of Hall Place in Bexley, Kent upon the death of his father on 5 July 1706 . He was High Sheriff of Kent in 1724.
Austen was elected Member of Parliament (MP) for New Romney, Kent on 29 April 1728 and held the seat until 1734. He was re-elected for the seat on 10 Feb 1736 and held the seat until 5 May 1741.
Austen died aged 46 and was buried in Churchdown, Gloucestershire.
Austen married Rachael Dashwood (c. 1706 – 16 May 1788), sister of Sir Francis Dashwood, a notorious rake. However, the marriage did not produce any children and he was succeeded in the baronetcy by his brother Sir Sheffield Austen.