Popsugar Entertainment Once Upon A Time Who Is Returning For the Once Upon a Time Series Finale? Once Upon a Time Is Bringing Back a Ton of Fan-Favorite Characters For the Series Finale 21 March 2018 by Kelsie Gibson View On One Page Photo 11 of 14 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 11 Keegan Tracy Tracy will reprise her role as the Blue Fairy. Previous Next Start Slideshow Once Upon A TimeTV