The coat of arms of San Marino probably originated in the fourteenth century. The official establishment took place on 6 April 1862 by a Decree of the Supreme Council; the same act introduced the crown on top of the shield.

There is little evidence regarding the official design until the mid-20th century. "The Flag Bulletin" vol. III, no. 2 from the winter of 1963–64 is reproducing on page 31 an "official plate showing the flag and arms of San Marino, [which] was a gift of the Sammarinese government, through its Consul in New York City." This plate was previously published in an official guide of the republic, from March 1963. In 2011, a new Law on the flag and coat of arms of San Marino presented a slightly simplified design, the main changes being that the branches have no more ramifications, the towers are square instead of round, and the gates are oriented now towards sinister.

The coat of arms of San Marino adorns among other things the flag of the country and the logo of the San Marino Football Federation.