Un Cuarto de Siglo (A Quarter of Century) (1995) is the twelfth album and third live album by Mexican rock and blues band El Tri.

It records a concert held on the 25th anniversary of the bound's formation under their original name "Three Souls in My Mind".

In the booklet Alex Lora thanks its followers as follows: Thanks to all the people who had supported us all this years and followed without prejudice our concerts, thanks for passing to your sons, as inheritance, the joy for our musicAll tracks by Alex Lora except where otherwise noted.