The most distant star ever observed is any contained in Galaxy MACS0647-JD, located 13.3 billion light years from earth. This galaxy is located at such a great distance that even with the aid of powerful orbital telescopes, it is not yet possible to make out individual stars.
Galaxies are composed of billions of stars that are all but impossible to observe individually at extreme distances. Light from the most distant observable galaxies has had to travel several billion years in order to reach the Earth. Images of these galaxies provide a window into the past, dating to a time just 420 million years after the formation of the universe.