CLS may refer to:
CLSCs (centre local de services communautaires, local community service centre) in Quebec are free clinics which are run and maintained by the provincial government.
In particle physics, CLs represent a statistical method for setting upper limits (also called exclusion limits) on model parameters, a particular form of interval estimation used for parameters that can take only non-negative values.
CLS Knights Surabaya is a basketball club based in Surabaya, East Java, Indonesia that plays in the Indonesian Basketball League.
Claspin is a protein that in humans is encoded by the CLSPN gene.
Calsyntenin-1 is a protein that in humans is encoded by the CLSTN1 gene.
CLS Communication is a language translation, editing and writing services company based in Switzerland.