1E

1E or 1-E may refer to:
 * 1st meridian east, a longitude coordinate
 * ISS 1E
 * Astra 1E, a communications satellite owned and operated by SES, and launched in 1995
 * California Proposition 1E (2009), a defeated California ballot proposition
 * 1E, UIC classification of the 2-10-0 train arrangement
 * 1E, a designator of celestial objects discovered via Einstein Observatory
 * 1E, inc - Software Company specializing in Digital Employee Experience (DEX) Gartner