Plan to spend 1.5 to 2 hours at Palais Galliera.
That’s enough time to walk through the main fashion exhibition at a relaxed pace, read the key displays, and spend a little extra time with standout garments, archival pieces, or themed rooms. If you’re a fashion/design enthusiast or the museum has a major temporary exhibition, keep 2.5 hours aside.
For a quick visit, 1 hour works, but it may feel rushed.