Eastlake was born in Plymouth. Trained by the architect Philip Hardwick (1792–1870), he popularized William Morris's notions of decorative arts in the Arts and Crafts style, becoming one of the principal exponents of the revived Early English or Modern Gothic style popular during the nineteenth century. He did not make any furniture; his designs were produced by professional cabinet makers. The style of furniture named after him, Eastlake style, flourished during the later half of the nineteenth century. A style of architecture, with old English and Gothic elements, is also named for him.
In 1868 he published Hints on Household Taste in Furniture, Upholstery and other Details, which was very influential in Britain, and later in the United States, where the book was published in 1872.
From 1866 to 1877 he was secretary to the Royal Institute of British Architects, and from 1878 to 1898 he was Keeper of the National Gallery, London. His uncle, Sir Charles Lock Eastlake PRA (born in 1793), was an earlier Keeper of the National Gallery, from 1843 to 1847, which, nowadays, results in much confusion between the two men, whose names are distinguished only by the presence or absence of an "e" in their middle names.
- This article incorporates text from a publication now in the public domain: "Eastlake, Charles Locke (DNB12)". Dictionary of National Biography. London: Smith, Elder & Co. 1885–1900.
- A History of the Gothic Revival: an Attempt to Show How the Taste for Mediæval Architecture, which Lingered in England during the Two Last Centuries Has since Been Encouraged and Developed. Publisher: Longmans, Green & Co., London 1872;
- Hints on Household Taste in Furniture, Upholstery, and Other Details. Edited by Charles C. Perkins. Publisher: J. R. Osgood, Boston 1874
- Notes on the Principal Pictures in the Brera Gallery at Milan. Publisher: Longmans and Co., London 1883;
- Notes on the Principal Pictures in the Louvre. Publisher: Longmans and Co., London 1883; 1883
- Notes on the Principal Pictures in the Old Pinakothek at Munich. Publisher: Longmans & Co, London 1884;
- Notes on the Principal Pictures in the Accademia in Venice, 1888
- Art for the Nation: Sir Charles Eastlake at the National Gallery. Exhibition at the National Gallery 27 July – 30 October 2011