The Children's Encyclopædia was an encyclopædia originated by Arthur Mee, and published by the Educational Book Company, a subsidiary of Amalgamated Press of London. It was published from 1908 to 1964. Walter M. Jackson's company Grolier acquired the rights to publish it in the U.S. under the name The Book of Knowledge (1910).
The encyclopædia was originally published in fortnightly parts between March 1908 and February 1910. Some readers could have bound their collections, but the first eight-volume sets were published in 1910. Each section contained a variety of articles, developing topics as it progressed. The work could be used as a conventional reference library, as the last volume had an alphabetical index, or each section could be read from start to finish. It was originally organised into sections but there were changes in subsequent editions. Some titles covered scientific subjects such as geology, biology and astronomy but such scientific terms were generally avoided.
Mee wrote an introduction called a "Greeting" and a "farewell". He took a strong interest in the "Book of Wonder", in which the Wise Man answered questions posed by children.
The illustrations were mostly anonymous but some illustrators included Susan Beatrice Pearse, C. E. Brock, Thomas Maybank, George F. Morrell, Dudley Heath, Charles Folkard, H. R. Millar, Alexander Francis Lydon, Arthur A. Dixon and Arthur Rackham. The books used photographs by Frank Hinkins, engravings, maps and graphics.
The encyclopædia broke ground in the approach to education, aiming to make learning interesting and enjoyable. Its articles were clearly written and intended to develop character and sense of duty.