The 25-year-old joins on a season-long deal that Villa describe as including a "conditional obligation to buy," while Crystal Palace call it an "option to buy," continuing an arrangement that began when Guessand first moved to Selhurst Park in January.
That January switch followed a difficult start to life at Villa Park. Guessand had joined Aston Villa only last August in a £26 million transfer but managed just two goals in 21 appearances across all competitions before his move to Palace turned his season around.
He scored his first Premier League goal in a 1-0 win over Wolves and came off the bench in the Conference League final victory over Rayo Vallecano in May, helping Palace lift their first major trophy. He also picked up a second European winner's medal from the campaign, having featured for Villa earlier in the season before Unai Emery's side went on to win the Europa League.
"I enjoyed it a lot last season because we played in Europe," Guessand said. "I know for the club it's not usual, but we played European football and had some good games, and some great nights at Selhurst Park.
"And of course, we finished with this amazing trophy. I enjoyed it because, obviously I like my teammates, and I like the way we are strong as a team.
"The last six months with Crystal Palace was great."
Guessand said his growing experience of continental football has left him hungry for more this season, both in Europe and domestically.
"It's been a few years now I'm playing in this type of game. I'm still excited to play because I know the level of this competition. I know the level of this team. I want to go as far as possible. Firstly in Europe because as I said, I played this competition before and I know we can achieve something. And then for the Premier League as well, I think we can compete with the best teams in the league."
The move gives Palace an established forward option as the club begin the defence of their Conference League title alongside a full Premier League campaign, with Guessand's familiarity with the squad seen as a valuable asset following his impact in the second half of last season.