The Terra-Return League (sometimes spelled "Terrareturn League") was a group and political movement that existed within the United Federation of Planets.
Formed on the Benecia colony, this political group was created on reference stardate 1/5708 with their Proclamation stating they wished an end to the Federation's policy of expansion. Furthermore, they wished for all humans to leave the outlying regions of space and return to the Terra system. This was because the League felt that humanity had not solved many of its own basic problems when it entered into space and as such resources were both abused and exploited on an interstellar level. This organization believed there was enough room for development on the inhabitable worlds within the Sol system which included Mars, Venus, Ceres, Titan, and Ganymede. Thus, the League advocated the dissolution of the Federation and that Earth observe a strict isolationist policy in regards to extra-solar activity.
The early conflicts with the Klingon Empire initially strengthened the position the Terra-Return League, which argued that the Klingons were simply responding to the provocation of Federation expansion. League activists regarded the Klingons as simply the latest "bogeyman" used to justify the expenses of Starfleet and colonial expansion, and tended to discount accounts of the Klingon's actual aggressiveness.
On stardate 1/7701 at the Babel Conference, the small but vocal minority that consisted of the League officially raised the point of disbanding the Federation. Despite their debate and impassioned speeches, the decision to keep the Federation was passed by an acceptable margin. (TOS reference: Spaceflight Chronology, FASA RPG module: The Four Years War)
- The League was part of the same social movement as the Back-to-Earth Movement organization led by Maxwell Grandisson III from the city of Atlanta on Earth, which had identical goals and took part in the same events (TOS novel: The Final Reflection). Whether they were organizationally connected or simply allied movements is unspecified, though the names would sometimes be used interchangably.