Scotland is part of the United Kingdom (see Scotland Facts) and although it has no passport requirements of it's own, a passport IS required to enter the UK.

If you enter Scotland from
another place in the UK, such as England, a passport IS NOT required as there are no borders between Scotland and England.
If Scotland is your entry point from
outside the UK, such as a flight from Toronto to Glasgow International Airport, a passport IS required. In this case you will be expected to go through passport control and customs.
Visitors to Scotland who are citizens of a European Union country still require a passport to enter the UK. Passports are required at all UK entry points, including Scotland.
If you have any questions about your passport requirements we recommend you contact either your national embassy or consulate in the UK or the UK embassy or consulate in your country of origin.