The large ensemble cast includes Morfydd Clark as a young Galadriel, "now a hardscrabble warrior leading the Northern Armies," who is determined to hunt down her brother's killer. She ends up adrift at sea with a new character named Halbrand (Charles Vickers). All we know about him is that he is "running from his past." Charles Edwards plays Celebrimbor, whom hardcore LOTR fans will recognize as the elven smith who forged the legendary rings.
Robert Aramayo plays a younger version of Elrond—"a canny young elven architect and politician." (Aramayo also played the young Eddard Stark on Game of Thrones.) And Maxim Baldry will play the infamous Isildur, ancestor of Aragorn, who eventually defeated Sauron but fell victim to the One Ring's corrupting power.
Among other new characters, Sophia Nomvete plays the dwarven Princess Disa, and Orwain Arthur plays Prince Durin IV, but there's no indication of what their relationship might be. Ismael Cruz Cordova plays a silvan elf named Arondir, and Nazanin Boniadi plays his love interest, Bronwyn, a single mom described as "a human village healer."
There's also a breed of hobbits known as the Harfoots, who mostly try to stay hidden and keep to themselves. But two curious young hobbits, Poppy Proudfellow and Nori Brandyfoot (played by Megan Richard and Markella Kavenagh, respectively), are more adventurous and somehow encounter "a mysterious lost man whose origin promises to be one of the show's enticing questions." That's probably The Stranger (Daniel Weyman). Other characters include the dwarf King Durin III (Peter Mullan). The streaming platform has not yet revealed who will be playing Sauron.