Ambrogio Annoni (Milan, 1882- id., 1954) was an Italian architect and restoration theorist, who worked as an official of the Superintendency of Monuments between 1910 and 1926, and as an assistant professor for more than forty years at the Polytechnic of Milan from 1910.

Annoni was the author or supervisor of numerous restorations, especially in Ravenna (where he was superintendent between 1920 and 1922), Pavia and Milan.

Among his interventions the following stand out:

The importance of his contribution to restoration theory is due to his denial of standardized methods: Annoni avoids abstract theorization and schematization in favor of the so-called case-by-case theory, as a method of adaptation to each project.

Annoni rejects the priority in the search for unity of style, as can be seen in the restoration of San Pietro in Gessate - which requires the maintenance of the baroque portal, in order to avoid a reconstruction in style - and of the Broletto in Pavia, a building in which he tries to bring to light and protect the multiple historical strata.

Some of his projects also show other solutions that are far from usual practice and that have paved the way for the inclusion of modern elements in historic buildings, such as in the reconstruction of the lower nave of the Basilica of Galliano, where he proposes the simple memory of the arches with a glass wall.

He was one of the first to highlight the importance of the main metrics in buildings as a means of historical-critical knowledge, as well as geometric architecture.

His attitude towards restoration can be summed up in his own words: