The authors agree in pointing to a Germanic origin for this surname, although they differ as to the exact root. E. Rossoni indicates that it derives from the medieval name Trottus or Trotta, coming from the Germanic Druht or its variant Trutten. As a notable historical detail, he notes that in the 12th century a female physician named Trotta appears in Salerno, considered one of the first women doctors in history. Rossoni also gathers early traces of its transformation into a surname: in the 14th century with the Piacentine Albertus Trottus, a jurist and professor in Ferrara, and in the 16th century with the bishop of Alessandria Guarneris Trottus.

V. Blunda, centred on Sicily, proposes that the surname derives from the Germanic personal name drudi, linked to the root that expresses loyalty and affection, the same one that gave the old Italian drudo ("lover, beloved person") and the old French dru. Blunda expressly rules out the association with the Italian verb trottare ("to trot"), considering it a folk etymology without foundation, since that verb has an independent onomatopoeic origin. Rossoni, on the other hand, maintains it as a valid alternative hypothesis, together with another that links the surname to the Calabrian term trotta ("trout").

As for its geographical distribution, Rossoni describes the surname as pan-Italian in scope, with a presence especially marked in the peninsular south. The variants Trotti and Trotto have specific zones of concentration in regions of the north and centre of Italy, such as the Varese, Milan and Brescia area, the Verona area, the Terni area, and also in Rome, Naples and Bari.