11/3

11/3 may refer to:
 * November 3 (month-day date notation)
 * March 11 (day-month date notation)
 * 11 shillings and 3 pence in UK predecimal currency
 * A type of hendecagram
 * 2004 Madrid train bombings
 * 2011 Tōhoku earthquake and tsunami
 * Fukushima Daiichi nuclear disaster, caused by the earthquake and tsunami