Passport validity
Your passport must be valid for at least 3 months.
its validity shall extend at least three months after the intended date of departure from the territory of the Member States
Visa rules · Tourist entry
Entry rules for Gibraltar from its official sources, and every passport we have a page for.
Gibraltar sets its own entry rules, which follow Schengen visa policy. A Schengen short-stay visa covers it, and a UK visa does not.
Official sources
Your passport must be valid for at least 3 months.
its validity shall extend at least three months after the intended date of departure from the territory of the Member States
Pick your passport for the full rule, its source quote and the check date.