[1] While the two clubs existed independently for many years, in 1941 a forced merger formed the TSG Rain am Lech.

In the spring of 1946, the two clubs decided to merge once more, this time by free choice and the TSV Rain am Lech was formed.

After its formation in 1920, The FC Rain entered the 2nd Kreisklasse Schwaben Nord, a league it performed rather well in the coming seasons.

Despite winning the title and promotion again in 1938–39 the FC Rain chose to withdraw from the league due to the outbreak of the war.

In 1949, the 2nd Kreisliga was renamed B-Klasse and the club belonged to this league for two seasons until winning promotion in 1951 to the now A-Klasse Nordschwaben.

In this league, the TSV Rain finished on top in its first season and earned promotion for the first time to the Landesliga Bayern-Süd (IV).

A 0–7 home defeat for the then fifth division club against a Bundesliga team was a highlight in the history for the small amateur side.

[3] Due to changes in the German league system in 2008, the third place qualified the club to take part in a promotion round for the Oberliga Bayern, something usually reserved for the second-placed team.

[4] Like in its past experiences when earning promotion to a higher league for the first time, the club found it a hard level to play at and success was much harder to come by.

The club had to continue its fight for Bayernliga survival in the post-season, having finished on equal points with Würzburger FV (14th) and SV Seligenporten (15th) and therefore required a set of deciders to be played, which it won.

At the end of the 2011–12 season the club managed to finish in the top nine of the Bayernliga and thereby directly qualified for the new tier four Regionalliga Bayern.