Couscous is not gluten-free. Couscous is made from semolina which comes from durum wheat. It would not be safe for someone with celiac disease or other gluten-related disorders.
I use quinoa instead of couscous in recipes/salads etc. It works very well as a replacement and has the added benefit of being a very nutritious whole grain. Just make sure that the quinoa is labeled gluten-free. You can read more about quinoa here: https://nationalceliac.org/celiac-disease-questions/quinoa/
Note: This information is provided by NCA and Katarina Mollo MEd, RDN, LDN, NCA's Director of Education. This information is meant for educational purposes only and is not intended to substitute for personalized medical advice or replace any medical advice provided directly to you by your health care provider. No liability is assumed by the NCA or Katarina Mollo, MEd, RDN, LDN by providing this information.