Final answer:
Kim Campbell was sworn in as the first and so far only Prime Minister of Canada on June 25th, 1993.
Step-by-step explanation:
The first and so far only Prime Minister of Canada to be sworn in on June 25th was Kim Campbell in the year 1993. She served as the Prime Minister of Canada from June 25, 1993, to November 4, 1993. Kim Campbell held this position after Brian Mulroney and before Jean Chrétien.