This Galileo Science Colloquium brings together members of the European scientific community and their international partners involved in the use of Galileo and other GNSS in their research. The various possibilities to use Galileo and other GNSS satellites for scientific purposes shall be reviewed. The Colloquium contributes to GNSS development in general based on scientific approaches, in particular to raise awareness of those in charge of Galileo development and operations as well as in development of recent scientific achievements in the field.