Crisis on Infinite Earths Giant is the Crisis on Infinite Earths tie-in comic. It was released digitally in two chapters on December 15, 2019, and January 19, 2020.
- The issue announced that another tie-in comic will be made to explain inconsistencies with Freedom Fighters: The Ray and Crisis on Earth-X.
- The issue was written midway through writing the scripts of the crossover. This results in the inconsistency of the issue and the crossover.
- The issue includes a page explaining the continuity of the issue.
- The issue's two parts take place between the scene when Harbinger travels to Earth-74 to recruit the universe's Waverider and the Monitor explains the Paragons to the heroes in Crisis on Infinite Earths: Part Two.
- As Earth-X was seen destroyed in the opening of Crisis on Infinite Earths: Part One, Marc Guggenheim explains that the scene takes place between Crisis on Infinite Earths: Part Two and Crisis on Infinite Earths: Part Three.
- Part of the continuity errors are solved in the second issue of the series.