Shazam 2 will start production in 2020.
In an interview with the Associated Press, star Zachary Levi revealed the script for the sequel was currently being written, and that he expects to start filming the movie "in late spring or early summer next year."
If Shazam 2 takes as long from filming to theaters as its predecessor, the movie will then likely hit theaters in 2021. Shazam! started filming January 2018 and arrived in theaters April 2019. However, there's also the possibility it might finish principal photography and end up having reshoots or extra time in post-production. If this date holds true, Shazam 2 will hit theaters before Aquaman 2, which is scheduled for 2022 despite the original film releasing in late 2018.
As to why Shazam 2's production is being pursued more actively, producer Peter Safran indicated Warner Bros. was actively pursuing a sequel due to the speed with which child actors age.
Shazam! made a little over $363 million at the box office, a modest sum for a DC Extended Universe film. However, the movie's budget was approximately $100 million, the lowest for any DCEU film. The plot of the sequel is unknown at this time.
Directed by David F. Sandberg, Shazam! stars Asher Angel as Billy Batson, Zachary Levi as Shazam, Mark Strong as Dr. Thaddeus Sivana, Djimon Hounsou as the ancient wizard Shazam, Grace Fulton as Mary Bromfield, Jack Dylan Grazer as Freddy Freeman, Ian Chen as Eugene Choi, Jovan Armand as Pedro Peña, Faithe Herman as Darla Dudley, Cooper Andrews as Victor Vásquez and Marta Milans as Rosa Vásquez. The film is scheduled to be released on digital HD on July 2 and Blu-ray and 4K UHD on July 16.