https://www.cnet.com/news/binge-doctor-who-on-iplayer/

That means you can marathon the adventures of Christopher Eccleston, David Tennant, Matt Smith and Peter Capaldi, including Christmas specials and the 50th anniversary starring John Hurt. The mini-episode starring Paul McGann is also included. And it's all free, right up to season 10 and the most recent episode Twice Upon a Time.

Seasons 1-9 of nu-Who are also available for a fee on Netflix.