On October 14, 2016, Bay announced that John Turturro would reprise his role as Seymour Simmons from the first three films, and that John Goodman would return to voice Hound.
Pada tanggal 14 Oktober 2016, Bay mengumumkan bahwa John Turturro akan mengembalikan perannya sebagai Seymour Simmons dari tiga film pertama, dan John Goodman akan kembali menyuarakan Hound.