The actor was paid $1.5m for reshoots of Ridley Scott's latest film, compared to less than $1,000 for co-star Michelle Williams.
Plummer and Williams were nominated for Golden Globes for their performances.
Wahlberg said: "Over the last few days my re-shoot fee for All the Money in the World has become an important topic of conversation.
"I 100% support the fight for fair pay and I'm donating the $1.5m to the Time's Up Legal Defence Fund in Michelle Williams' name."
His donation was welcomed by other Hollywood figures on social media, with Mark Ruffalo hailing it as a "classy and admirable move" and Eva Longoria tweeting: "Yes yes yes! Thank you @mark_wahlberg for not only supporting @TIMESUPNW but supporting fair pay for women!"
Another $500,000 (£364,000) will be donated to Time's Up by talent agency William Morris Endeavor, which represents Williams and Wahlberg.
"We are committed to being part of the solution," it said in a statement.
It also aims to generate a fund to provide legal support to people who have experienced sexual harassment in the workplace.