DVD-R DL (DL stands for Dual Layer), also called DVD-R9, is a derivative of the DVD-R format standard. DVD-R DL discs hold 8.54 GB (7.96 GiB) per side by utilizing two recordable dye layers, each capable of storing nearly the 4.7 gigabyte (GB) (4.38 GB) of a single layer disc -almost doubling the total disc capacity. Discs can be read in many DVD devices (older units are less compatible) and can only be written using DVD-R DL compatible recorders. It is part of optical disc recording technologies for digital recording to optical disc.

DVD-R DL has compatibility issues with legacy DVD-ROM drives known as pickup head overrun. To avoid this issue, the two layers of the disc need to be equally recorded. But this is a contradiction with the sequential nature of the DVD recording. Thus DVD Forum under Pioneer's lead developed a technology known as Layer Jump Recording (LJR), which incrementally record smaller sections of each layer to maintain compatibility with DVD-ROM drives.

Dual Layer recording allows DVD-R and DVD+R discs to store significantly more data, up to 8.5 GB per side, per disc, compared with 4.7 GB for single-layer discs. DVD-R DL was developed for the DVD Forum by Pioneer Corporation, DVD+R DL was developed for the DVD+RW Alliance by Philips and Mitsubishi Kagaku Media (MKM).

DVD-R is a DVD recordable format. A DVD-R typically has a storage capacity of 4.71 GB. Pioneer has also developed an 8.5 GB dual layer version, DVD-R DL, which appeared on the market in 2005.

Data on a DVD-R cannot be changed, whereas a DVD-RW (rewritable DVD) can be rewritten multiple (1000+) times. DVD-R(W) is one of three competing industry standard DVD recordable formats; the others are DVD+R(W) and DVD-RAM.

The DVD-R format was developed by Pioneer in 1997. It is supported by most DVD players, and is approved by the DVD Forum.

The larger storage capacity of a DVD-R compared to a CD-R is achieved through smaller pit size and smaller track pitch of the groove spiral which guides the laser beam. Consequently, more pits can be written on the same physical sized disc. In order to write smaller pits onto the recording dye layer a red laser beam with a wavelength of 640 nm (for general use recordable DVD, versus a wavelength of 780 nm for CD-R) is used in conjunction with a higher numerical aperture lens. Because of this shorter wavelength, DVD-R and DVD+R use different dyes from CD-R to properly absorb this wavelength.