There's more than one place called '''Saint John''', '''Saint John's''' or '''St. John's''':
Saint John's - the capital city, on the island of Antigua
Saint John Parish - one of Antigua's 6 parishes
Saint John Parish - one of the island's 11 parishes
Saint John - the largest city in the province of New Brunswick
Saint John River Valley - in the province of New Brunswick
St. John's - the capital of the province of Newfoundland and Labrador
Saint John Parish - one of the island's 10 parishes
Saint John Parish - one of the island's 6 parishes
Saint John's (Montserrat)
Saint John (Virgin Islands) - smallest of the three main islands