Flying into Paris then taking train to Barcelona. Any suggestions on how to get from Barcelona to Santiago de Compostela
If you don't want to make stops along the way (there are many interesting options), flying is the way to go. You can look for flights on skyscanner.com. For the random April day I checked, I found non-stop flights on Vueling and RyanAir, but two of the three were very early in the morning. If you need a mid-day departure, it might be worth looking at flights to Vigo and A Coruna. You could probably get to Santiago de Compostela from either of those airports within about 1 to 2 hours.
Flew Vueling last October for around €65 including checked bag.