Matt Damon’s Oppenheimer Character Explained (& What The Actor’s Said About His Role)

Matt Damon’s Oppenheimer role is as memorable as any in the celebrated historical epic. The cast of Oppenheimer is filled with some of the biggest heavyweight actors playing some of the most important people in recent American history. It’s a bit darkly humorous that it took an Englishman like Christopher Nolan to thoroughly examine one of the most defining moments of the United States. Dozens of real critical figures are accounted for in Oppenheimer, some for a scene, others as main characters.

Despite playing a supporting role, Damon is one of the biggest stars in the mᴀssive cast of Oppenheimer. Along with writing and starring in Good Will Hunting, Damon is known for the Jason Bourne movies, the Ocean’s movies, The Martian, and The Departed. He will next lead Christopher Nolan’s cast of The Odyssey with their work together in Oppenheimer likely securing that leading role for the actor. As exciting as that upcoming movie is, Damon’s work in Oppenheimer is exceptional, with a fascinating character to work with.

Matt Damon Plays Lt. General Leslie Groves In Oppenheimer

Groves Was An Officer In The United States Army Corps Of Engineers

Matt Damon co-stars in Oppenheimer as Lt. General Leslie Groves, a real-life United States Army Corps of Engineers officer. Born on August 17, 1896, Groves quickly learned the ways of the military thanks to his father, Leslie Richard Groves Sr., a Presbyterian chaplain in the Army, and Groves Jr. spent his early life moving from Army post to Army post (via The NMUSA). After graduating from West Point, he was ᴀssigned to the U.S. Army Corps of Engineers as a 2nd lieutenant and spent his early career working on construction projects around the nation.

After his successful work on building the Pentagon, mentioned in Oppenheimer, Groves was selected to head the then-secret Manhattan Project. Groves had a reputation for having a big ego, and it’s notable that in Oppenheimer, he calls out Robert (Cillian Murphy) for his. Perhaps it takes one to know one. Colonel Kenneth D. Nichols, who knew Groves, said (via AHF),

“First, General Groves is the biggest S.O.B. I have ever worked for. He is most demanding. He is most critical. He is always a driver, never a praiser. He is abrasive and sarcastic. He disregards all normal organizational channels. He is extremely intelligent. He has the guts to make timely, difficult decisions. He is the most egotistical man I know. He knows he is right and so sticks by his decision. He abounds with energy and expects everyone to work as hard, or even harder, than he does… if I had to do my part of the atomic bomb project over again and had the privilege of picking my boss, I would pick General Groves.”

Damon plays this crusty and hard-edged yet incredibly capable figure extremely well. He perfectly portrays why Groves could be hard to deal with but also why he was the right man for the job, and why he and Oppenheimer got on so well, at least as co-workers.

What Oppenheimer Leaves Out About Lt. General Leslie Groves

Nolan’s Groves Is Very Close To The Real Man


Leslie Groves (Matt Damon) dressed in his military uniform in Oppenheimer.

The Lt. General Leslie Groves in Oppenheimer closely matches the real-life Lt. General Leslie Groves, at least for the years when the atomic bomb was being built. The film does not go into his backstory, nor much of his later life, such as when he retired in 1968 and became the Vice President of Sperry Rand Corporation, a now-defunct aerospace and defense contractor (via Atomic Archive). What Oppenheimer does leave out is that “Colonel” Groves was actually promoted to the rank of Temporary Brigadier General at the outset of the Manhattan Project.

What Matt Damon Has Said About His Oppenheimer Role

Damon Understood The Difficulty A Military Man Would Have With A Group Of Scientists


Matt Damon as Leslie Groves looking serious in Oppenheimer.

Matt Damon gave a lot of thought to his portrayal of the General, as any Academy Award-nominated actor should. He said (via Military Times),

“The frustration [for] Groves — what he lived with as a military person — he suddenly finds himself in charge of a bunch of civilians who don’t really recognize the chain of command.”

Groves had to handle a town of talented but arrogant scientists, and the most talented and most arrogant was the one he personally selected to put in charge of the whole project. It’s a much different world than he’s used to, and Damon works hard to show the frustration and strain put on him throughout. Damon said about his character’s relationship with Oppenheimer,

“They both appreciated each other — they helped each other fulfill each other’s ambitions. Each couldn’t have done it without the other. There was a lot of genuine affection there.”

Scenes of that genuine affection between the characters, like the one right before the bomb test, are some of Matt Damon’s best work in Oppenheimer.

What Critics Said About Matt Damon’s Performance

Damon Received Strong Praise For His Supporting Turn

Leslie Groves as Matt Damon looking confused in Oppenheimer

The mᴀssive cast of Oppenheimer saw a lot of acclaim for the ensemble, with several highlights. Both Cillian Murphy and Robert Downey Jr. won Oscars for their performances, while Emily Blunt was nominated. Some of the supporting cast also received strong responses for their brief screen time, including Josh Hartnett, David Krumholtz, Casey Affleck, and Alden Ehrenreich. It might seem as though Matt Damon’s performance was somewhat lost in the acclaim, but there were plenty of critics who praised his work in Oppenheimer.

THR pointed to the layers of Damon’s performances with delivering some unexpected moments in the movie, such as when the harsh and combative exterior of Groves’ drops late in the movie to offer some support for his embattled friend:

A gruff career military man probably better suited to the battlefield than to War Department jobs, Groves has a stern manner but an underlying respect for Oppenheimer’s genius, a duality that Damon plays to moving effect in the 1954 hearing.

There were also a number of critics who highlighted the relationship between Oppenheimer and Groves as a standout aspect of the movie. Collider‘s review spoke to Damon’s adding fascinating elements to this relationship that evolved over time:

Also noteworthy is Matt Damon as Leslie Groves, who puts Oppenheimer in his position at The Manhattan Project. The relationship between Oppenheimer and Groves is one of the most complex in the film, and it’s fascinating to watch how it shifts over the years.

However, even though he may not have received the same accolades and attention as his co-stars, there were some who felt Damon gave one of the best performances in Oppenheimer, with Mashable’s review being particularly praising of the actor:

Matt Damon proved to be the most surprising and thrilling performer in the bunch… As the general bullying about the scientists of Los Alamos, he’s a jarring breath of fresh air. Where they ponder and speak with clever poetry and sophistication, he speaks bluntly with no concern for hurt feelings or wounded egos, and so nearly every one of his lines hits like a punchline. It’s brazen and bizarrely funny in the midst of so much darkness. But the comic relief here is more than that. Damon’s general is also one of the chief symbols of the danger of nationalism in Oppenheimer. His resolute atтιтude and bravado become as much a red flag as an amusement.

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