By

By or BY may refer to:

Places

 * By, Doubs, France, a commune
 * By, Norway, a village

Codes

 * Belarus ISO country code
 * .by, country-code top-level domain for Belarus
 * Burundi, obsolete FIPS Pub 10-4 and NATO digram country codes
 * TUI Airways IATA airline code, formerly Thomson Airways, Thomsonfly and Britannia Airways

Other uses

 * John By (1779–1836), British military engineer famous for his work in Canada
 * CC BY, a Creative Commons attribution license
 * Budget year, a synonym for fiscal year