The fantasy series, starring Henry Cavill, has had fans binge watching in their droves following its launch on 20 December.
Sex Education, The Umbrella Academy, You and Top Boy are also among the most popular Netflix series releases of 2019.
Not on the shortlist is The Crown, starring Olivia Coleman as the current Queen Elizabeth. It returned for series three earlier this year with a brand new cast as Coleman took over the role from Claire Foy.
Based on the game of the same name, The Witcher follows the adventures of lonesome monster hunter Geralt of Rivia, played by the Man Of Steel star.
Witchers are supernatural monster slayers who have gone through a series of grueling rituals and training to become almost immortal in their power.
Top 10 most popular series streamed on Netflix UK in 2019
The Umbrella Academy
Their abilities include overwhelming strength and resilience in combat, increased lifespan, and fast immune system to help speed up healing if wounded in battle.
Showrunner Lauren Hissirch recently teased that the show could run for seven seasons as they have so much material planned for Geralt and the universe he explores.
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Speaking to SFX Magazine about a possible second season, she joked: ‘Second season? I’ve done it for seven seasons!’
‘We don’t have a second season yet – God willing we will,’ she then warned.
‘Right now it’s just about, “How do you set up stories that really capture audiences for years at a time?”’
‘The worst thing we could do is put all of our energies just into season one, and not be thinking about where these characters can grow to.’
The Witcher is available to stream on Netflix now.
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