The former wrestler reportedly earned $87.5m (£67m) between 1 June 2019 and 1 June 2020, including $23.5m for the Netflix thriller Red Notice.
He also made money from his fitness clothing line, Project Rock.
The 10 top earners combined made $545.5m this year - more than a quarter of that from Netflix, Forbes said.
Johnson's Red Notice co-star Ryan Reynolds was the second-highest paid actor, with earnings of $71.5m. Among his movie deals were $20m, also for Red Notice, and $20m for Six Underground, another Netflix film.
Third on the list was actor and producer Mark Wahlberg, who earned $58m, while Ben Affleck came in fourth and Vin Diesel fifth.
Indian actor Akshay Kumar was the only Bollywood star in the top 10. He came in sixth place with earnings of $48.5m, which Forbes said mostly came from product endorsement deals.
Also on the list were Hamilton creator Lin-Manuel Miranda, actors Will Smith and Adam Sandler, and veteran movie star Jackie Chan.
The highest-paid female actors for the same period are released as a separate list, and are yet to be announced.
Last year, Scarlett Johansson topped the list with an income of $56m - less than that year's seventh-placed male actor.