• 
  Manny Montana

  Zeno
• 
  Brenda Song

  tanti Frida / Frida
• 
  Diedrich Bader

  Admiral Crick
• 
  Dee Bradley Baker

  Merc
• 
  Grey Griffin

  Stella
• 
  Danny Jacobs

  Admiral Watson
• 
  Tom Kenny

  Leo Callisto
• 
  Olivia Munn

  Phoebe Callisto

• 
  Cullen McCarthy

  Miles Callisto
• 
  Fiona Bishop

  Loretta Callisto
• 
  Sam Lavagnino

  20 episodes, 2015-2017
• 
  Issac Ryan Brown

  21 episodes, 2015-2018
• 
  Justin Felbinger

  Miles Callisto
• 
  Kerstin Dietrich

  33 episodes, 2016-2018
• 
  Ivy Bishop

  Mirandos

• 
  Neil deGrasse Tyson

  Main Title Narration
• 
  Elan Garfias

  Commander Nemex
• 
  John DiMaggio

  Aggro
• 
  Adrian Grenier

  Captain Joe