The String Quartet No. 14 in C♯ minor, Op. 131, was completed by Ludwig van Beethoven in 1826. It is the last-composed of a trio of string quartets, written in the order Opp. 132, 130, 131.

The term string quartet refers to either a type of musical composition or a group of four people who play them. Many composers from the mid-18th century onwards wrote string quartets. The associated musical ensemble consists of two violinists, a violist, and a cellist. The double bass is almost never used in the ensemble mainly because it would sound too loud and heavy.