The Israel international midfielder heads to The Valley, and could make his debut in the Addicks’ Championship fixture against Stoke City on Saturday.
The loan arrangement includes a recall option in January, when the transfer window reopens.
Head coach Graham Potter said, “Beram has trained really well since I arrived at the club and been a pleasure to work with during my short time here.
“This is a good move at this stage in his career, and gives him a chance to play regularly. On behalf of all at the club, I would like to wish Beram all the very best for the season ahead at Charlton.”
Kayal arrived at the club from Celtic in January 2015, and scored on his debut in a 3-2 defeat to Nottingham Forest.
The Israeli featured 45 times in all competitions during the 2015/16 campaign, and won the club’s Player of the Season award.
He missed three months of the 2016/17 season with an ankle injury, but returned to action at the turn of the New Year and was part of Albion’s promotion-winning squad.
Having helped Albion to the Premier League, he made a total of 37 top-flight appearances. He scored his first goal at that level in a 1-0 win at Newcastle United early last season.