1A

1A or 1-A can refer to either:
* 1A (comics)
* "1-A", a story by Thomas M. Disch
* 1. A Slovenian Basketball League
* Adcox 1-A, a biplane built in Portland, USA in 1929
* Alpha-1A adrenergic receptor, a human gene
* Arginine vasopressin receptor 1A, a human gene
* Astra 1A, the first satellite launched and operated by Société Européenne des Satellites
* California Proposition 1A (2004),
* Class 1-A, a classification of the Selective Service System
* Croatian 1A Volleyball League
* Essex bus routes 1 and 1A
* Interferon beta-1a, a drug in the interferon family
* List of highways numbered 1A disambiguation page
* List of X-1A flights disambiguation page
* Little Joe 1A, a 1959 unmanned NASA launch
* Melatonin receptor 1A, a human gene
* Meltwater pulse 1A, a period of rapid deglacialization that took place 14.7-14.2 thousand years ago
* Mercury-Redstone 1A, a 1969 NASA mission
* Metallothionein 1A, a human gene
* MH-1A, a nuclear power reactor and the first floating nuclear power station
* NAFL Division 1A, an amateur football league
* Packard 1A-1500, a 1929 12 cylinder liquid-cooled 60 degree Vee piston aircraft engine
* Pre-1A, a grade in the Jewish day school structure of education
* Secretoglobin, family 1A, member 1 (uteroglobin), a human gene
* ShinMaywa US-1A, a Japanese anti-submarine warfare aircraft
* Sisu 1A, a homebuilt sailplane
* Turksat 1A, a satellite