Will doing my CS PhD by distance learning make it harder to get a job as a professor? I've seen very reputable universities such as Georgia Tech and Berkley, to name a few, offering MSc degrees in Computer Science through distance learning. However, I'm not seeing the same distance learning opportunity available for PhD programs. After a Google search, I've found few well-known universities that take off-campus students - I only recall University of Florida - for PhD degrees.

I want to earn a PhD because I would like to become a Professor after that, so I want to know if doing a distance learning PhD program would harm my  employment opportunity.
Yes, it will make it harder to get a job as a professor of computer science.

A distance learning PhD is not well suited for learning certain skills that one would learn in a traditional PhD, as described in more detail at Are there any aspects of PhD work that do not translate well to distance learning?. Some of these skills are important for getting a job as a professor and/or doing the job of a professor. For example, you would not get any teaching experience in a distance learning course, and most faculty applicants are expected to have at least some teaching experience.

Furthermore, by doing a PhD by distance learning, you miss out on a lot of the networking and exposure to other academics that happens in a good computer science PhD program. This plays a major role in getting a faculty job afterwards.

The exception to this is if you were to get a job where the PhD is necessary only as a formality. For example, if you are already so well known in your field that every university wants to hire you, but can't because their HR departments insist that faculty candidates must have a PhD, then a distance learning PhD might be sufficient.