The Eagles trio, who have made a combined 672 appearances between them (Hughes 82, Schlupp 230 and Ward 360), have all extended their deals until the summer of 2025.
All three players have served as core members of the first-team squad and remain in the plans of new manager Oliver Glasner, who replaced Roy Hodgson in mid-February.
Captain Ward has been at Palace since 2012 and the 34-year-old has featured regularly as either a right-back or right-sided centre-back this season, making 25 Premier League appearances.
Schlupp, meanwhile, is enjoying his seventh season at Selhurst Park and the versatile 31-year-old has chipped in with two goals and three assists in 28 top-flight outings so far this season, including a stunning strike in a 1-1 draw with Fulham at the end of last month.
As for Hughes, he joined Palace in 2021 for an initial £6m and the 29-year-old midfielder has since started 22 of his 27 Premier League games this season, including 10 outings under Glasner.
Hughes, Schlupp, Ward commit futures to Palace
Speaking to the club's official website about the trio of new deal, chairman Steve Parish said: "In any Premier League squad, it remains vitally important to strike the right balance between youth and experience, with a squad of players all capable of driving the club forwards on and off the pitch.
"As well as playing a pivotal role on the pitch, Will, Jeff and Joel are natural leaders in the dressing room who embody the Crystal Palace DNA and who help set a culture of the highest standards at the training ground.
"We are delighted that they will be with us next season to help further our exciting early progress under Oliver Glasner."
Palace have also revealed that they are discussions with defender Nathaniel Clyne and backup goalkeeper Remi Matthews about extending their contracts at the club - both players are out of contract at the end of June.
Meanwhile, the Eagles have announced that James Tomkins and Jairo Riedewald will leave the club when their contracts expire in the summer.
Tomkins, Riedewald to leave Crystal Palace at end of season
Tomkins, 35, joined the Eagles in 2016 and has since made a total of 135 appearances in all competitions, although just four of those have been made this season.
The defender, who has scored 10 goals for the club including two memorable strikes in separate matches against Brighton & Hove Albion, was an integral member of the Palace side that equalled its joint-best Premier League points tally in 2018-19.
Riedewald, meanwhile, moved to Selhurst Park from Ajax in 2017 and has played a total 95 times across all tournaments, including eight top-flight outings this term.
The versatile 27-year-old scored three times for the Eagles, including a superb strike against Newcastle in a 2-1 win at St James' Park, as well as the winning goal against Stoke City to send Palace through to the 2022 FA Cup quarter-finals.
"James and Jairo have both shown superb dedication and professionalism during their long spells at the club," said Parish. "They have not only been important players at the heart of our recent squads, but also role models to our younger talents.
"We are grateful to them both for their contributions on and off the pitch, and I would like to personally wish them well for the next chapters in their respective careers."
Both Tomkins and Riedewald will be hoping to feature in some capacity across Palace's final two Premier League fixtures away against Wolverhampton Wanderers on Saturday and at home to Aston Villa on May 19.