Qualys, Inc. provides cloud security, compliance and related services and is based in Foster City, California. Qualys provides vulnerability management solutions using a "software as a service" (SaaS) model. It has added cloud-based compliance and web application security offerings.

Qualys has over 10,300 customers in more than 130 countries, including a majority of the Forbes Global 100. The company has strategic partnerships with major managed services providers and consulting organizations including BT, Dell SecureWorks, Fujitsu, IBM, NTT, Symantec, Verizon, and Wipro. The company is also a founding member of the Cloud Security Alliance (CSA).