Johnston and his wife first did a walk-about at the E.A. Rawlinson Centre for the Arts on Tuesday afternoon.
Johnston then met with more than 400 students from six area schools, who asked him questions about his job.
Students have a vital role in Canada's future, he said.
"I hope that as young people, as students, understand more about what makes us free, why the rule of law is important to us, that it ensures so many of those freedoms and liberties that we enjoy and shouldn't take for granted, they would say, 'My, I want do my best to be sure that continues."
The governor general was also meeting with chiefs and senators from the Prince Albert Grand Council.
Later Tuesday, Johnston presented three residents from Prince Albert with the Caring Canadian Award as the Albert Jenkins fieldhouse.
Johnston and his wife will be in Saskatchewan until Thursday.
Johnston is to take part in events to mark the 100th anniversary of the legislature in Regina.