1-9 may refer to:
0s, the first "decade" of the AD/CE time system (AD 1–9) 1% rule (Internet culture), also known as the 1–9–90 rule Two services of the New York City Subway which formerly ran together: 1 (New York City Subway service) 9 (New York City Subway service) U.S. Route 1/9 concurrency in northern New Jersey Emergency telephone number for city police in Morocco January 9, 9th day at the 1st month September 1, 1st day in the 9th month
See also 1/9 (disambiguation) Numeral system