:For the English clergyman, see Robert Cornthwaite (Bishop)

Robert Cornthwaite (born October 24, 1984 in Blackburn, Lancashire, England) is an English-Australian football (soccer) player. He is a tall centre back or right full back who currently plays for Adelaide United in the Australian A-League. He has also made representative appearances for the Australian Under 23 team, the 'Olyroos', in their 2008 Olympic qualifying campaign. Robert also has a nickname of 'Cornflakes', and is considered widely to be one of the best young defenders in the A-League. He scored the opening goal in just the third minute against Pohang Steelers in Adelaide United's opening game of the 2008 Asian Champion League.

Robert Cornthwaite (b. 9 May 1818, Preston - d. 16 June 1890) was a Roman Catholic bishop.

On 9 November 1845, aged 27 Cornthwaite was ordained a priest by Nicholas Wiseman (later Cardinal Wiseman).

From 1851 until 1857 he was Rector of the Venerable English College, Rome, and later in 1861 was ordained Bishop of the Diocese of Beverley.

In 1878 the Diocese of Beverley was divided into two and Bishop Cornthwaite continued to serve as the Bishop of Leeds until his death in 1890.