According to Hollywood Reporter, returning to their roles alongside Jason Sudeikis (Lasso) are Hannah Waddingham, Brett Goldstein, Juno Temple, Jeremy Swift, and Brendan Hunt.
Seven new actors have also joined the cast. Among the newcomers are Tanya Reynolds ("Sex Education"), Faye Marsay ("Andor"), Jude Mac, and Abbie Hern ("Enola Holmes 2"). Ted's son Henry is now played by Grant Feely — he's replacing young Gus Turner.

Source:
imdb.com
What season 4 will be about
Filming began in Kansas City, Ted's hometown. In this new chapter, Ted returns to Richmond — but not to coach the men's team. Instead, he's training the women's second division club. So we're getting sports, motivation, humor, and a touch of absurdity again — everything we loved about the first seasons.What the first three seasons were about
Originally, "Ted Lasso" was just a character from NBC Sports commercials. But the story of an American football coach finding himself at an English soccer club turned out to be so warm and human that it quickly grew into a full series.
Source:
imdb.com
What critics and viewers are saying
On Rotten Tomatoes, the series has 90% approval, Metacritic gives it 77 points, and IMDb rates it a solid 8.8.Viewers praise the series for its "perfect blend of American and British humor," "positive energy," and "acting performances."
The release date for season four hasn't been revealed yet. But I think we won't have to wait long for the first trailer. Earlier, we at zoomboola.com reported on the start of filming for the "Scrubs" sequel series.