The article discusses variants of the names of St. Petersburg, used primarily in the letters of Peter the Great and his contemporaries. According to the generally accepted point of view, the first option is Санктпитербурх, appearing in the Book of Mars, which, however, was created at the time when St. Petersburg was already the capital and its name was widely known. In the letters of Peter the Great himself, dating back to the beginning of the construction of a new capital, there are about 20 spellings of the full name of the fortress and the city. The writings used by Peter have signs of orthographic, phonetic and orthographic, and etymological variation, which reflects the living language processes of the first third of the 18^th century. Various spellings of the toponym Petersburg can be found in the same texts. The etymological version of Petropol, which also appeared in 1703, in the first third of the 18 ^th century is found mainly in high-style texts, which are rooted in Church Slavonic. The unofficial name of St. Petersburg is Peter, which was originally part of the complex name of the city in separate writing. From the middle of the 18^th century, it has become widely used as an independent spoken name. Analysis of the available materials shows that none of the variants of the name of St. Petersburg can claim the title of the first and none of them arose later.