Charles William Grenfell (17 March 1823 – 4 May 1861) was a British Liberal Party politician.
His mother was Lady Georgiana Frances, daughter of William Molyneux, 2nd Earl of Sefton, while Henry Grenfell was his younger brother.
Grenfell entered Parliament for Sandwich in 1847, a seat he held until 1852.
Grenfell married Georgiana Caroline, daughter of William Lascelles, in 1852.
His eldest son William Grenfell was also a politician and was raised to the peerage as Baron Desborough in 1905.