LCO may refer to:
- Local Cable Operator - resell for MSO(s)
- Las Campanas Observatory - an astronomical observatory in Chile
- Libraries Connect Ohio
- Legislative Competence Order
- London Chamber Orchestra
- London Contemporary Orchestra
- Lithuanian Chamber Orchestra
- lipochitin oligosaccharide / lipo-chitin oligosaccharide
- The IATA airport code of Lague Airport, in the Republic of the Congo