Nowadays, no works in Tuvinian linguistics consider the specificity of anthroponyms borrowed from the Mongolian language, peculiarities of their adaptation and functioning in Tuvan Buddhist texts. Meanwhile, studying this word group can shed light on the formation and functioning of the Tuvan Buddhist vocabulary and reveal additional data on the history of the formation of lexical and phonetic features of the Tuvinian language associated with the Tuvan- Mongolian language and cultural contacts. It is worth studying Mongolian borrowed anthroponyms in the Tuvan translation of the Buddhist work “Üleger-Dalay” – the sutra “Sea of Proverbs,” the only Tuvan Buddhist source not influenced by the Russian-speaking Buddhist literature actively published and translated into Tuvan since the 1990s. The specificity of the Mongolian anthroponyms analyzed is that their nominative function simultaneously characterizes the referent and reflects its essence. They are divided into six thematic groups: names-epithets of Buddha, names associated with Buddhist practices, names indicating the inner qualities of a person, names of celestials, names associated with natural objects, names with somatismatic components indicating the appearance or associated with the circumstances of the referent’s birth. They are divided into three structural types: 1-component, 2-component (most of them), and 3-component. All borrowed Mongolian names have mostly been adapted to the phonetic norms of the Tuvinian language. The main ways of phonetic transformation are assimilation, formation of long vowels, replacement of some sounds and sound combinations with other sounds, simplification of vowels.