SafeDisc is a copy protection program for Microsoft Windows applications and games distributed on optical disc. Created by Macrovision Corporation, it was aimed to hinder disc duplication. The program was first introduced in 1998 and was discontinued on March 31, 2009.

Although the stated use is to prevent piracy, many, including the Electronic Frontier Foundation, believe it is used to restrict one's fair-use rights.

There have been several editions of SafeDisc over the years. Each one had the goal of making discs harder to copy. The last revision was marketed as SafeDisc Advanced.

The early versions of SafeDisc did not make the discs very difficult to copy. Later versions 2.9+ could produce discs that are difficult to copy or reverse engineer, requiring specific burners capable of emulating the "weak sectors" and odd data formats that are characteristic of SafeDisc.

Shortly after the release of Windows 10 in 2015, Microsoft announced that games with SafeDisc DRM would not run on the operating system, citing security concerns over the software due to the way in which it becomes "deeply embedded" in the system. Microsoft stated that supporting SafeDisc could have been a possible loophole for computer viruses to exploit. Support for SafeDisc on earlier versions of Windows was withdrawn upon the release of update number 3086255 in 2015.

Previous versions of SafeDisc were overcome by disc image emulator software such as Daemon Tools and Alcohol 120%. SafeDisc currently blacklists such software, meaning that those who want to use this method must install additional software to cloak the mounter; examples include CureRom and Y.A.S.U.

Another potential attack on SafeDisc is to pull the encrypted application out of the archive it is contained in. All SafeDisc encrypted discs contain an ICD file, an encrypted format used by SafeDisc to ensure that the original CD is loaded. UnSafeDisc circumvents and decrypts SafeDisc encrypted files by opening the ICD file format, decrypting it, and converting it to an EXE file. However, each program requires a specific patch to enable full functionality.

SafeDisc adds a unique digital signature to the optical media at the time of replication. Each time a SafeDisc-protected program runs, the SafeDisc authenticator performs various security checks and verifies the SafeDisc signature on the optical media. The authentication process takes about 10 to 20 seconds. Once verification has been established, the sequence is complete and the program will start normally. The SafeDisc signature is designed to be difficult to copy or transfer from the original media. (For example, it might change as a result of error correction during the copying process.) Certain multimedia programs are designed to run from the PC's hard drive without accessing files from the program disc after the initial installation. SafeDisc will permit this as long as the consumer retains the original CD or DVD, which is required for authentication each time the program is launched. Failure to place the original disc in the drive when loading the program will prevent validation of the SafeDisc signature.