Charlton signed striker Svetoslav Todorov from Portsmouth and goalkeeper Nicky Weaver from Manchester City on free transfers on Wednesday.
Todorov (left) and Weaver are the latest arrivals at Charlton
Weaver, 28, signed a three-year deal after 10 years at City - during which he made more than 200 appearances.
Striker Todorov, also 28, fell down the pecking order at Portsmouth last season and has signed a one-year deal.
"They're two proven Premiership players who are now Championship players," boss Alan Pardew told Charlton's website.
"Nicky hasn't had the breaks in his career that he has deserved, but this is a great opportunity for him while Svetoslav's quality and precision, which is proven in this division, will be very important to us, especially in home games."
The duo have become Pardew's seventh and eighth signings of the summer.
Todorov said he was confident of making a positive impact at The Valley.
"Leaving Portsmouth was a big decision for me but I'm looking forward to playing for Charlton," he said.
"I like the way Alan Pardew's teams play. I saw his teams at Reading and at West Ham and liked their style."