A Latin Dictionary (or Harpers' Latin Dictionary, often referred to as Lewis and Short or L&S) is a popular English-language lexicographical work of the Latin language. Lewis and Short were the names of its editors, Charlton T. Lewis and Charles Short. It was derived from the 1850 English translation of an earlier Latin-German dictionary.

The division of labour between the two editors was remarkably unequal. Short, a very thorough but slow worker, produced material for the letters A through C, but B and C were lost by Harpers, meaning that his work now only appears in the letter A, while Lewis, who worked in the time he could spare from his law practice, was solely responsible for the entries beginning with the letters B through Z. In 1890 Lewis published a heavily abridged version of the dictionary, entitled An Elementary Latin Dictionary, for the use of students. Sometimes called the Elementary Lewis.

Lewis and Short remains a standard reference work for medievalists, renaissance specialists, and early modernists, as the dictionary covers Late and Medieval Latin.