| Character Name | Japanese Voice Actor/Actress | English Voice Actor/Actress |
| Lina Inverse | Megumi Hayashibara | Lisa Ortiz;
Cynthia Martinez (movies) |
| Gourry Gabriev | Yasunori Matsumoto | Eric Stuart |
| Zelgadis Graywords | Hikaru Midorikawa | Dan Cronin (Slayers eps. 2-10);
Crispin Freeman (Slayers eps. 18 & on) |
| Amelia Wil Tesla Seyruun | Masami Suzuki | Joani Baker (Slayers eps. 11-13);
Veronica Taylor (Slayers eps. 14 & on) |
| Filia Ul Copt | Houku Kuwashima | Tara Jayne |
| Xellos Metallium | Akira Ishida | David Moo |
| Rezo Graywords | Takehito Koyasu | Charles Rolf |
| Copy Rezo | Takehito Koyasu | Peter Davis |
| Zolf | Mosato Hirana | Stan Hart |
| Rodimus | Katsutshi Hoki | Junior Rigenback |
| Dilgear | Hirohi Kakegawa | Jimmy Zoppi |
| Vrumugun | Hiroshi Enaka | Carter Cathcart (Slayers ep. 13);
Jimmy Zoppi (Slayers eps. 14-18) |
| Zangulus | Bin Shimada | Ted Lewis (Slayers eps. 11-12, NEXT);
Liam Omalley (Slayers ep. 13) |
| Sylphiel Nels Rada | Yumi Touma | Stacia Crawford |
| Eris | Etsuko Ishikawa | Rachael Nanstad |
| Philionel El De Seyruun | Masahiro Anzai | Matt Black (Slayers eps. 11-13);
Jimmy Zoppi (Slayers eps. 24 & on) |
| Martina Zoana Mel Navratilova | Mifugu Hiiragi | Rachael Lillis |
| Gaav the Demon Dragon King | Kazue Ikura | Vinnie Penna |
| Hellmaster Phibrizzo | Wataru Takagi | Scottie Ray |
| Naga the White Serpent | Maria Kawaura | Kelly Manison |