Oddsmakers at the Westgate Las Vegas SuperBook set the Red Sox as minus-135 favorites in early betting, with the Dodgers made plus-115 to win the Series.
That means a $135 bet on the Red Sox will pay $100, while a $100 bet on the Dodgers will pay $115.
Odds on the individual games will be posted when pitching matchups are named.
The Dodgers, who went 92-71 in the regular season, advanced to the World Series with Saturday's 5-1 win over the Milwaukee Brewers in Game 7 of the NLCS. Boston, which went 108-54, won the AL pennant in a five-game series with the Houston Astros.
The Associated Press contributed to this report.