Absolutely. Apple, Amazon, Google, Vudu, Movies Anywhere (off the top of my head).
What I recently learned is that some physical discs will come with download codes that can be used, once, on any of these services. I was gifted the Alien box set which was nice but I don’t have a Blu-ray player. The code allowed me to add the films to my iTunes account.
Now, how long I can watch those movies until a license runs out is another question. I’ve yet to find a way to download a movie to disc for backup. Because, technically, you don’t buy a movie, you buy the license to watch it. This is even the case for physical discs.