Is the word festival the same in Brazilian and European Portuguese?

Yes

The word "festival" is identical in spelling, meaning, and grammar in both Brazilian and Continental Portuguese. The only difference lies in pronunciation: in Brazil, the final "l" is typically vocalized as a "u" sound (making it sound like fes-chi-vau), whereas in Portugal, the "l" is more distinctly articulated (often velarized) and the unstressed vowels are more closed.

Brazilian Portuguese Examples

1. Eu amo ir ao festival de música. (I love going to the music festival.)
2. O festival de cinema vai começar amanhã. (The film festival is going to start tomorrow.)
3. Teve um festival de comida muito legal no parque. (There was a really cool food festival in the park.)
4. Você viu a programação do festival? (Did you see the festival schedule?)
5. O festival de inverno é minha parte favorita do ano. (The winter festival is my favorite part of the year.)

Portuguese (Portugal) Examples

1. Adoro ir ao festival de música. (I adore going to the music festival.)
2. O festival de cinema começa amanhã. (The film festival starts tomorrow.)
3. Houve um festival de gastronomia muito bom no parque. (There was a very good food festival in the park.)
4. Já viste o cartaz do festival? (Have you seen the festival lineup/poster?)
5. O festival de inverno é a minha parte favorita do ano. (The winter festival is my favorite part of the year.)