Abstract: In this article, the author analyzes the Portuguese colonial architecture in the countries of South Asia in the period from the XVI to XVIII centuries. The author examines the military, civil and religious architecture built by the Portuguese during their presence in the South Asian colonies. Special attention is paid to the Portuguese colonial architecture of India (especially Goa) and Macau. Buildings in Singapore, Thailand, Malaysia and other former Portuguese colonies in South Asia are also considered. The author studies the process of formation and features of a special Portuguese colonial style in military (fortification), civil and religious (cult) architecture. The features in the design, decoration, as well as building materials of buildings are revealed. The novelty of the study lies in the fact that for the first time the samples of Portuguese colonial architecture in South Asia and their architectural features were comprehensively considered. The main conclusions of this study are the following. Firstly, on the one hand, the European architectural tradition has enriched the culture of the South Asian region. At the same time, different types of buildings show different degrees of influence. Secondly, on the other hand, Portuguese colonial architecture in South Asia itself has undergone significant changes under the influence of local cultural and climatic factors. Many of the changes made to classical European building designs were dictated by the weather and climatic features of the area. The choice of material was dictated by climatic and geological features. The culture of local civilizations also influenced the decoration and decoration of Portuguese buildings.