1A

1A or 1-A may refer to:

Arts and entertainment

 * 1A (comics), a comic book robot
 * 1A (radio program), an American radio program

Politics

 * First Amendment (disambiguation), the first amendment of various legislation
 * First Amendment (disambiguation), the first amendment of various legislation

Science and technology

 * Group 1A, an obsolete designation for the group 1 elements
 * AMY1A, a human gene
 * Alpha-1A adrenergic receptor, a human gene
 * Interferon beta-1a, a drug
 * Meltwater pulse 1A, a period of rapid post-glacial sea level rise, 13,500–14,700 years ago
 * Melatonin receptor 1A, a human gene
 * Metallothionein 1A, a human gene
 * MH-1A, a nuclear power reactor and the first floating nuclear power station
 * Vasopressin receptor 1A, a major receptor type for vasopressin

Sports

 * Croatian 1A Volleyball League
 * 1. A SKL, the 2002–2006 name of Premier A Slovenian Basketball League

Transportation, military and space

 * Adcox 1-A, an American 1929 biplane
 * Astra 1A, a 1988 satellite
 * Class 1-A, an American military service classification
 * Little Joe 1A, a 1959 unmanned NASA launch
 * Mercury-Redstone 1A, a 1969 NASA mission
 * Packard 1A-1500, a 1929 piston aircraft engine
 * Shin Meiwa US-1A, a Japanese anti-submarine warfare aircraft
 * Sisu 1A, an American 1950s sailplane
 * Türksat 1A, a Turkish satellite
 * List of highways numbered 1A