This is a list of space travelers by first flight. The table is listed in chronological order from the date of first flight. The table adheres to a common definition of a space traveller; the Fédération Aéronautique Internationale criterion of achieving an altitude higher than 100 km (62 mi; 330,000 ft), thereby crossing the FAI-defined Kármán line. The criteria for determining who has achieved human spaceflight vary. Personnel who qualify only for the United States Astronaut Badge, awarded to those who achieve an altitude of 50 mi (80 km; 264,000 ft), are listed at the X-15's highest flights and the VSS Unity test flights.

All entries are dated from launch time in Coordinated Universal Time (UTC), which on occasion is one day earlier than the local date of launches from sites in the Eastern Hemisphere such as Baikonur and one day later than the local date of launches from sites in the Western Hemisphere such as Cape Canaveral.

As a rule, dual nationals fly under a single flag when flying as professional spacecrew and/or when flying on government-operated spacecraft, and this is the flag they are listed under in the table. For the spaceflights of dual nationals who are private citizens flying on commercial spacecraft as ordinary passengers, the flags displayed are those of their countries of birth, unless the space traveller did not hold citizenship of that country and/or otherwise made clear (s)he intended to represent a different nationality.