In 1992, he was appointed President of 20th Century Fox International, where he was responsible for the marketing and distribution for the studio's films and television programs.

[11] At Fox, Gianopulos supported a closer relationship between Hollywood and Silicon Valley,[8] and he was instrumental in the launch of iTunes, the Hulu streaming service, and other internet-driven offerings.

[12][13] In March 2017, he was named chairman and CEO of Paramount Pictures, after the dismissal of the late Brad Grey.

He put into production the box office blockbuster Top Gun: Maverick (2022), as well as Sonic the Hedgehog 2 (2022), A Quiet Place Part II (2021), IF (2024), The Lost City (2022) and Mission: Impossible – Dead Reckoning Part One (2023) and Mission: Impossible – The Final Reckoning (2025).

[18][19] It was announced that CBS and Viacom (parent company of Paramount Pictures) would recombine as ViacomCBS in December 2019.

Jim Gianopulos was confirmed to continue on as chairman and CEO of Paramount Pictures under the merged ViacomCBS.