Most people watch by release order and enjoy it fine — but chronological order lets you see how the MCU builds its world. Here is the real tradeoff: release order has better pacing and reveals (you understand character arcs as the filmmakers intended), while chronological order lets you follow the timeline of events in the MCU universe itself. Neither is "wrong."
This is how Marvel Studios released the films. It works because directors and writers designed reveals, plot twists, and character introductions around this sequence. You get the best storytelling experience. Start with Iron Man (2008) and follow the MCU's official release schedule through to the latest films.
Watch events in the order they happen in the MCU timeline:
The catch: Chronological order creates weird pacing problems. You watch Captain America's WW2 origin story, then jump forward 50 years and watch 1990s Captain Marvel with different visual effects. Plot threads feel disjointed because supporting characters were not introduced yet in the timeline. Emotional payoffs land weaker because you have not watched the character development in the intended order.
Watch Phases 1-3 in release order (Iron Man through Endgame). Once you know the MCU's structure and characters, go back and watch Disney+ series in chronological order around the main timeline. This gives you the best storytelling first, then deeper world-building second.
Pro tip: If you are doing a full rewatch in 2026, Phase 5 and beyond have some series that fit better in the timeline than in release order. Ask yourself: Do I care more about seeing how the filmmakers reveal the story, or do I care about watching events in universe chronology? If it is the former, release order wins every time.