Frank Doelger announced in 2020 at Cannes, as part of the International Market for Television Programs (MIPTV), that his next TV series The Swarm was going to be the adaptation of novel The Swarm by Frank Schätzing. The series was produced by ZDF within the framework set by the European Alliance, with France Télévisions and RAI, and in co-production with ORF, SRF, Viaplay Group and Hulu Japan who formed the joint venture 'Schwarm TV Productions GmbH & Co KG'. The series is the first project from Doelger-led Intaglio Films, a joint venture formed in 2019 by the German production company Beta Film and ZDF Enterprises.
The international cast is selected by casting director Robert Sterne, and includes European actors, Cécile de France, Sharon Duncan-Brewster, Jack Greenlees, Lydia Wilson, Krista Kosonen, Alexander Karim, Leonie Benesch and German star Barbara Sukowa with Japanese actors Takuya Kimura and Takehiro Hira. American actors Rosabell Laurenti Sellers and Dutch Johnson, and Canadian Joshua Odjick also feature in the series.
The script was written by Steven Lally, Marissa Lestrade, Chris Lunt and Michael A. Walker in consultation with experts, such as polar and deep-sea researcher Professor Antje Boetius, from the Alfred Wegener Institute, and Dr Jon Copley, professor of Ocean Exploration from the University of Southampton. Barbara Eder, Luke Watson and Philipp Stölzl directed the series.
Filming began on 7 June 2021 in Italy and Belgium.The final scenes of the series were filmed at a EUR23 million underwater studio on the outskirts of Brussels.