Collier's Encyclopedia

The Collier's Encyclopedia or Collier's Encyclopedia is a general encyclopedia of the United States. It was first published in 20 volumes between 1950-1951 and in 1962 it was expanded to 24 volumes. It can be considered one of the three major contemporary English-language printed encyclopedias, along with the Encyclopedia Britannica and the Encyclopedia Americana.

The 1997 edition had 23,000 entries. It does not have many short entries, as related topics are usually consolidated into long articles. A high percentage of the illustrations are in color. Bibliographies are found in the last volume at the end of articles. One volume contains the essential index with 450,000 entries (1997 edition). It has a version on CD-ROM. The first to be published in 1996. The Collier Annual yearbook is also published.

Collier's Encyclopedia remains the main and only English encyclopedia not to have had an online version, since the rights were divided, in the way that the printing rights were granted to one company (Atlas) and the rights of online publishing were acquired by Microsoft, consequently creating the Encarta encyclopedia.