1942: Santanni and Trantor are human-colonized extra-solar planets featured in a number of Isaac Asimov's stories, e.g., in his Foundation series. They were introduced in his novelette "Black Friar of the Flame", first published in Planet Stories, Spring 1942, available at the Internet Archive:
"What good are your rebellions?" came the weary reply. "Are the Lhasinu so
much more terrible than the oligarchy of Humans that rules Santanni or the dictator that rules Trantor. If the Lhasinu are not Human, they are at least intelligent. Loarism must live at peace with the rulers."
There may well be earlier examples of named human-colonized extra-solar planets in science fiction. Note, however, that the accepted answer to the question First story to describe humans colonizing another planet? is a 1928 story:
1928: "The Second Swarm", a novelette by Joseph Schlossel, was first published in Amazing Stories Quarterly, Spring 1928, available at the Internet Archive, and reprinted in Science Fiction Classics, Summer 1968, also available at the Internet Archive.
In view of this, it seems unlikely that we will find named extra-solar human colony worlds from before 1928. (The colonized planets in Schlossel's 1928 story are extra-solar, but as far as I can tell without reading it word for word, they are not named.)