The Houston Astros' seven-game World Series win over the Dodgers averaged 18.9 million viewers on Fox, down 19% from the 23.4 million average for the Chicago Cubs' seven-game victory over Cleveland last year for their first title since 1908.
The total audience on Fox's three outlets averaged 19.56 million, the network said Thursday. That included an average of 476,000 viewers on Fox Deportes, up 34% from 355,000 last year, and a digital audience average of 183,000 on Fox Sports Go, an increase of 4%.
Viewers on Fox were up 37% from San Francisco's seven-game win over Kansas City in 2014, which averaged 13.8 million on Fox.
This year's Series averaged a 10.7 rating and 20 share, down from a 13.1/23 last year. That was the highest-rated World Series since 2004, when Boston defeated St. Louis for its first title since 1918.
This was the second-highest rated World Series since the New York Yankees beat Philadelphia over six games in 2009.
Fox said 106 million viewers watched the Series at some point, down from 115 million last year.
Tony La Russa and Dave Dombrowski have been talking about working together again since meeting more than three decades ago.
That reunion will finally happen with a Boston Red Sox franchise that continues to shake things up in its pursuit of another World Series championship.
The Red Sox hired La Russa on Thursday to serve as a vice president and special assistant on its baseball operations staff. He'll work for Dombrowski, the team's president of baseball operations, in player development and consultation with the major and minor league staffs.
La Russa, 73, served in a similar capacity with the Arizona Diamondbacks the last four seasons.
"It was an opportunity that I was excited about," La Russa said. "Everything you do professionally, if somehow there's a personal connection, I think it adds something to the opportunity. Dave and I go way back."
La Russa was a first-time manager and Dombrowski an energetic young executive with the Chicago White Sox when their careers first crossed paths in the mid-1980s.