His last day on the air will be June 26.
Bernie, as he is known to listeners, has reported on key political events for decades, from the 1984 shooting in the National Assembly to the 1995 sovereignty referendum to, most recently, his coverage of the death of former premier Jacques Parizeau.
Since joining CBC, he has worked as news assignment editor, producer, national reporter and host of CBC Radio's Homerun and Radio Noon.
More recently, he's served as CBC's senior Quebec political analyst.
"Over the years, Bernie has guided our audience through some of this province's most intense and memorable moments," Shelagh Kinch, managing director of CBC Quebec, said in a statement.
"We will miss his exceptional journalism, his deep political knowledge and his extensive understanding of how this province works."
In 1998, he co-created C'est la vie, an award-winning CBC Radio program about life in French-speaking Canada.
St-Laurent has also guest hosted various CBC Radio programs including The Current, Sounds Like Canada, As It Happens, The House and Cross Country Check-up and contributed to a number of Radio-Canada radio and television programs.
In 2012, he received the Award of Excellence from the Commissioner of Official Languages.