The 22-year-old, who has scored 12 tries in his 24 caps, sustained the injury during an England training session earlier this week, and the Premiership club have set no time frame for his return.
Watson started all three games in England's whitewash of Australia earlier this year.
"Anthony Watson broke his jaw in the England training camp earlier this week," Bath director of rugby Todd Blackadder told the club's website (www.bathrugby.com).
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"It's too early for a full medical prognosis on how long he'll be out for, but it's likely he'll miss the Autumn internationals."
England hopeful Sam Jones was also ruled out of the Autumn fixtures after fracturing his leg during a training session with the national team.
England, unbeaten this year, host South Africa at Twickenham on Nov. 12 before meeting Fiji, Argentina and Australia.
(Writing by Nivedita Shankar in Bengaluru; Editing by Toby Davis)
