Kristen Wiig will star alongside Matt Damon, Christoph Waltz and Hong Chau in Paramount’s social satire “Downsizing” with Alexander Payne directing.

Wiig is taking the place of Reese Witherspoon, who withdrew recently due to scheduling conflicts.

“Downsizing” centers on an Omaha man who joins the throngs of people undergoing a new process that reduces people to a tiny fraction of their size before moving to one of the many communities of small people that are sprouting up around the world.

Payne is co-writing the script with Jim Taylor. The duo won an Oscar for best adapted screenplay for “Sideways” and collaborated on the scripts for “Citizen Ruth,” “Election,” “Jurassic Park III,” “About Schmidt” and “I Now Pronounce You Chuck and Larry.”

“Downsizing” will be produced by Payne and Mark Johnson and will begin production this spring. Taylor and Jim Burke are exec producing.

Payne’s directing credits include “Citizen Ruth,” “Election,” “About Schmidt,” “Sideways,” “The Descendants” and “Nebraska.” Variety reported on March 10 that Waltz and Chau had joined the project.

Wiig starred on “Saturday Night Live” for eight seasons. Her feature credits include “Bridesmaids,” “Girl Most Likely,” “The Secret Life of Walter Mitty,” the “Despicable Me” franchise, “The Skeleton Twins,” “The Martian” and the upcoming “Ghostbusters” on July 15.

Wiig is repped by UTA and attorney Karl Austen. The news was first reported by Deadline Hollywood.