Most resumes don't need references on them. Employers ask for them later, usually once they are close to an offer.
Leave them off by default
Names and phone numbers take space and share other people's details with everyone you apply to. "References available on request" is assumed, so it can go too.
When to include them
- The job advert asks for references with the application.
- It is the custom where you are applying: some countries, the public sector and academic jobs expect them.
- A reference is so well known in your field that the name itself helps.
Choose and prepare them
Pick two or three people who have seen your work recently: managers first, then senior colleagues or clients. Ask them before you give their names, tell them about the job, and remind them of the work you did together. A prepared reference is a much better reference.
Keep them ready
Keep their names, roles and contact details in one place so you can send them when asked. In JSON Resume the references section holds quotes from people you've worked with, which some themes show; you can hide fields you'd rather keep off your public page.