Tennant stars as demon Crowley alongside Michael Sheen's angel Aziraphale, and he's bringing his son and father-in-law along for season 2.
According to their public CVs, House of the Dragon star Ty has been cast as a character called Ennon, while Davison, who's known for playing the Fifth Doctor in Doctor Who, will play a character called Alistair.
RadioTimes.com has contacted Amazon Studios for comment.
The series, based on the novel by Neil Gaiman and Terry Pratchett, won fans across the world with season 1 and followed the representatives of Heaven and Hell as they tried to stop the arrival of the Antichrist – not an easy feat.
Fans have closely followed the second season's filming and, while there's no specific release date just yet, Good Omens season 2 is expected to drop on Prime Video in the summer of 2023.
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Gaiman previously teased the upcoming series, saying: "In this season we get to have new adventures with old friends, to solve some extremely mysterious mysteries, and we encounter some entirely new humans (living, dead, and otherwise), angels, and demons.
"We were lucky in the first season to have so many outstanding actors taking part, so I took pleasure in inviting people back, wherever we could, some in the roles they played originally, some in new parts written just for them."
Tennant and Sheen will, of course, be back to lead the charge, while various cast members are back but in brand new roles.
Miranda Richardson is also starring in a new role as Shacks, the demon who has replaced Crowley in his role, while Shelley Conn takes over Anna Maxwell Martin's role as Beelzebub.
Additionally, Donna Preston will be playing brand-new character Mrs Sandwich, and other new angels added to the cast are Saraqael (Liz Carr) and Muriel (Quelin Sepulveda).
Meanwhile, other cast members from season 1 set to return in brand new roles include Paul Adeyefa (Bancroft, Ransom) and Michael McKean (This Is Spinal Tap, Better Call Saul).
Good Omens season 1 is available to watch in full on Amazon Prime Video – try Amazon Prime Video for free for 30 days.