Did Rabbi Moshe Feinstein ever formally receive semicha? From whom? I recall reading that he studied a great deal with his father, and that his first responsum was written "at his father's orders."
He (Rav Moshe) studied with his father and also in yeshivas located in Slutsk, Shklov and Amstislav, before being appointed rabbi of Lubań where he served for sixteen years. (Wikipedia)
He (Rav Moshe)joined the yeshiva of R' Isser Zalman Meltzer in Slutzk at the age of twelve, where he also learned under the tutelage of HaRav Pesach Pruskin, zt"l. When the latter opened his own yeshiva in Shklov, R' Moshe went with him and recounted that at the grand opening ceremony of the new yeshiva, R' Isser Zalman himself was present. Dei'ah veDibur
There seems to be no lack of Rabbis that would have/could have given Reb Moshe smicha aside from his father, however I was unable to find an establishment that would have given him smicha, however I am not even sure how many establishments of that nature existed during his early years.