Sean Penn won Best Supporting Actor at the Oscars for his role in One Battle After Another at the 2026 Academy Awards.

Quick Scoop: Who Won Supporting Actor?

If you’re searching “who won supporting actor” in the context of the most recent Oscars , the answer is:

  • Winner: Sean Penn.
  • Category: Best Supporting Actor (Academy Awards).
  • Film: One Battle After Another.
  • Ceremony: 98th Academy Awards (held in 2026, honoring 2025 films).

He plays Colonel Steven J. Lockjaw, a military figure whose dark, obsessive arc is central to the film’s emotional punch.

Why This Win Is A Big Deal

  • This Oscar makes Sean Penn a three-time acting winner, putting him in a very small club of male actors with three Academy Awards.
  • His previous wins were:
    • Best Actor for Mystic River (2004).
* Best Actor for _Milk_ (2009).
  • With this Supporting Actor win, he joins legendary names like Daniel Day-Lewis and Jack Nicholson in the “triple-Oscar” tier.

From a narrative point of view, awards watchers had already seen this coming when he won the Supporting Actor prize at the 2026 Actor Awards (formerly the SAG Awards) for the same role, often a strong predictor for the Oscars.

Recent Supporting Actor Context

To anchor the timeline around “who won supporting actor”:

  • 2024 Oscars (97th): Kieran Culkin won Best Supporting Actor for playing Benjamin “Benji” Kaplan in A Real Pain.
  • 2025 Oscars (97th year of films, awarded at the 2026 98th ceremony): Sean Penn is listed as the most recent Supporting Actor winner for One Battle After Another in up-to-date records.

So, if someone on a forum asks “Who won supporting actor?” right now in early 2026 , they almost certainly mean Sean Penn for One Battle After Another.

Mini FAQ: “Who Won Supporting Actor?”

  1. Q: Are we talking Oscars or other awards?
    • The phrase usually refers to the Academy Award for Best Supporting Actor unless otherwise specified (BAFTA, Golden Globes, SAG/Actor Awards all have similar categories).
  1. Q: Is this also aligned with guild awards?
    • Yes. Sean Penn also won the Supporting Actor prize at the 2026 Actor Awards (formerly SAG Awards) for the same performance, strengthening his Oscar campaign.
  1. Q: If I meant an earlier year (like 2024)?
    • Then the answer would change to Kieran Culkin for A Real Pain , but that is no longer the “latest” Supporting Actor winner.

Bottom note: Information gathered from public forums or data available on the internet and portrayed here.