Jadeite (ジェダイト Jedaito) is the first of the Four Kings of Heaven to appear. In her Materials Collection, Naoko Takeuchi describes him as being about 18 years old in appearance, making him the second-youngest, while in the live-action series he is the youngest. He is the head of the Dark Kingdom's Far-Eastern Division:Act 2 and is named after the mineral jadeite.
Jadeite's mission is to track down the Silver Crystal but eventually changes to gathering life energy to awaken Queen Metaria. He has very little interaction with the other Four Kings of Heaven, only briefly being seen with and mocked by Nephrite. He expresses an attraction to Sailor Mars and is the first one killed when Rei uses her Akuryo Taisan technique. After Jadeite's death, Nephrite vows to exact revenge as he preserves Jadeite's skeleton in a glass coffin. In the later side story Casablanca Memories, Zoisite also tries to avenge Jadeite. Jadeite is briefly revived and was able to remember the Golden Kingdom and his time as a military officer of Prince Endymion before being turned into the stone from which his name was derived. The piece of jadeite (along with the stones for the other three Kings of Heaven) are kept by Mamoru Chiba where he uses them to call upon his Kings of Heaven for advice.
In the first anime adaptation, hunting energy is Jadeite's primary mission. He is misogynistic, hostile, and antagonistic towards women. After failing numerous times, Beryl freezes Jadeite to death for his incompetence and Nephrite succeeds him. In the live-action series, Jadeite is totally subservient to Beryl, for which she rewards him with her favor, sending him on missions that range from gathering energy to spying on his fellow warriors to attacking the Sailor Soldiers directly. He disappears early in the series reverting to crystalline form due to an injury from one of his battles, but is revived by Metaria. Firmly loyal to Beryl, he rejects Endymion as his true master until the series finale where he stays with Beryl as her castle collapses around her.
In Sailor Moon Crystal, Jadeite survives the battle against Sailor Mars, but Beryl sends Nephrite to fulfill their mission. In his past life, he was the love interest of Sailor Mars. He is killed by Metaria along with the other Kings of Heaven in Episode 12. He is the Knight of patience and harmony.
In the original Japanese series, he is voiced by Masaya Onosaka. In Crystal, he is voiced by Daisuke Kishio. In the DIC English adaptation, his name was changed to Jedite and is voiced by Tony Daniels. In the Viz Media English adaptation, his voice is supplied by Todd Haberkorn. In the live-action series he was portrayed by Jun Masuo, and was portrayed in the musicals by Susumu Futabashi and Yuhka Asami.