The 45-year-old knuckleballer planned to make the announcement at the team's spring training facility at a news conference Friday evening.
After two seasons with the Pittsburgh Pirates, the right-hander signed as a minor-league free agent in April 1995. He was 186-168 with a 4.43 ERA with the Red Sox. Only Roger Clemens and Cy Young had more wins (192) with the team.
Wakefield is first in team history with 3,006 innings and 430 starts, and second in games and strikeouts.
For his career, Wakefield was 200-180 with a 4.41 ERA He was 7-8 with a 5.12 ERA last season in 23 starts and 10 relief appearances.