|Portrayed By||Mark Goddard|
|First Appearance||"No Place to Hide"|
|Last Appearance||"Junkyard of Space"|
|Also Known As||Major West|
|Affiliations||United Global Space Force|
Major Don West is the pilot of the Jupiter 2. Don's military training has proved useful in resolving a number of tense moments. He is also adept at overpowering aliens with his strength, but despite this he has suffered injuries more often than anyone else in the crew. This may be partly due to the fact that he has a susceptibility to concussions which makes it easier for him to fall unconscious if he hits his head hard. Don has a varied rapport with the others on the mission. If it were up to Don, Dr. Smith would be left behind. Don respects John Robinson, but sometimes questions his judgement. He is obviously attracted to Judy, but his feelings for her are often implied rather than overt. Despite being a top-notch pilot, Don seems to have a problem avoiding crash landings. Don often reveals a violent temper that must be occasionally reined in by Prof. Robinson. During the latter part of the series, Don showed signs of mental instability. Killing Don off in the unmade 4th season was considered, according to fan rumour.