Reading pair Sean Morrison and Jordan Obita have both signed new contracts at the Madejski Stadium.
Bayern Munich defender Jerome Boateng has signed a three-year contract extension.
Crystal Palace youngster Kyle De Silva has expressed his delight after signing a new long-term contract at the club.
The 18-year-old has been handed a three-year deal with the option of a further year after breaking into the first team this term and making seven appearances.
De Silva is a product of the club's thriving youth system and made his debut against Derby earlier this year in the FA Cup.
He told the club's official website: "This is the club I supported as a boy so I was delighted to sign.
"I didn't really expect to make as many appearances as I did last season, I was training (with the first team) since Christmas so I got comfortable by the time I made those appearances.
"To start against Reading and Southampton were good experiences because they both got promoted.
"Now the aim is that first goal, trying to nail down a regular spot and (keep) working hard."