Guy Williams Prof. John Robinson Actor June Lockhart Maureen Robinson Actor Mark Goddard Don West Actor Marta Kristen Judy Robinson Actor Bill Mumy Will Robinson Actor Angela Cartwright Penny Robinson Actor Jonathan Harris Dr. Zachary Smith Actor Dick Tufeld Robot Actor Reta Shaw Aunt Clara Simms Guest Star Walter Sande Sheriff George Baxendale Guest Star Robert Easton Newsman Lacy Guest Star Harry Harvey Grover Guest Star Helen Kleeb Phone operator Rachel Guest Star Anne Dore First Selectman Guest Star Donald Losby Davey Simms Guest Star Keith Taylor Theodore Guest Star Johnny Tuohy First boy Guest Star Irwin Allen Producer Peter Packer Writer Nathan Juran Director