Leeds United's Jordan Botaka
The 23-year-old, who can play as a winger or as a forward, completed the move earlier this week.
Charlton boss Slade is pleased to have signed the DR Congo international and has spoken highly of the attacker.
“Jordan is a strong boy, he’s really pacey and quick,” Slade told Charlton’s official website.
“He’s very impressive in one-on-one situations and likes to take players on. He’s still young at 23 and is still learning about the game over here.
“He could be a real threat at this level because he’s very strong when you give him the ball – he’s very creative and we’re very happy to have him for the season ahead.”
Botaka joined Leeds from Dutch side Excelsior in the summer of 2015. The 23-year-old was handed a two-year contract, as reported by BBC Sport at the time, and he arrived in England with a good reputation.
Much was expected of the DR Congo international at Elland Road, but the youngster did not have a great 2015-16 season.
Botaka struggled for playing time last season and could make just 13 Championship appearances for the West Yorkshire outfit, creating only 11 chances in the process.
Charlton will take on Northampton Town at The Valley in League One on Saturday afternoon.