St. Andrew's Day is the feast day of Saint Andrew. It is celebrated on the 30th of November. Saint Andrew is the patron saint of Scotland and many other countries. St. Andrew's Day is Scotland's official national day and bank holiday.

The celebration of St. Andrew in late Autumn dates from the reign of Malcolm III (1034–1093). This was for very practical reasons. At that time it was not possible to keep all the animals over a cold winter for there would not have been enough grazing or hay for them all, so many were slaughtered and their carcasses preserved for winter food for people. November 30 was a time when everyone did this, and had a feast at the same time before winter really set in.

St. Andrew's Day, like many other saint's days worldwide, is more of a Victorian event, when it was fashionable to think romantically of the past. This is also when the day began to be marked with feasts again.

Relics of the Apostle Andrew are kept at St Mary's Roman Catholic Cathedral, Edinburgh.

The Scottish flag, the saltire, is also connected to St. Andrew because of the way he was crucified on a diagonal cross.