OLS or Ols may refer to:

• Oleśnica (German: Öls), Poland
• Operation Lone Star, Texas border operation
• Optical landing system, U.S. Navy landing system
• Order of Luthuli in Silver, a South African honour
• Ordinary least squares, a method used in regression analysis for estimating linear models
• Ottawa Linux Symposium, tech conference held annually from 1999 to 2014
• Oulun Luistinseura, a Finnish multi-sports club
• The Sims 3: Outdoor Living Stuff, the third stuff pack to The Sims 3
• Nogales International Airport, Arizona, US (IATA code)