Normally not palpable. Sometimes it is.

Palpation Maneuvers
1) "Pron": Thumbs penetrate the right hypochondrium at the level of the external edge of the rectus.

Murphy's sign: Is the inspiratory arrest (due to sharp pain) when pressure is exerted against the gallbladder.

Courvoisier-Terrier's sign: Palpable, non-tender gallbladder in a jaundiced Patient (malignancy).

See the Abdomen page.