In an announcement on Twitter, Netflix has confirmed that there will be a fourth season for the Castlevania animated series. There is no word on when the fourth season will be airing, but given that there has at least been a year in between each season, there is a very good chance that we will not be seeing the fourth season until 2021.
https://twitter.com/NXOnNetflix/status/1243600966407995392
There is a small chance (this is just speculative, by the way), that Netflix might want to move things along faster. With the COVID-19 virus outbreak spreading throughout the world, many people have been staying home a lot more for work or study, meaning that more people will be turning to streaming services like Netflix more than ever.
We’re already seeing how movie studios are planning on releasing movies to digital earlier than usual, due to the lack of people going to cinemas, so maybe, just maybe, Castlevania’s fourth season could arrive earlier than expected.