双倍数据率同步动态随机访问内存（英语：Double Data Rate Synchronous Dynamic Random Access Memory，简称DDR SDRAM）为具有双倍数据传输率的SDRAM，其数据传输速度为系统时脉的两倍，由于速度增加，其传输性能优于传统的SDRAM。

DDR SDRAM 在系统时钟的上升沿和下降沿都可以进行数据传输。

JEDEC为DDR存储器设立了速度规范，并分为了以下两个部分：按内存芯片分类和按内存模块分类。

Double data rate synchronous dynamic random-access memory (DDR SDRAM) is a class of memory integrated circuits used in computers. DDR SDRAM, also called DDR1 SDRAM, has been superseded by DDR2 SDRAM, DDR3 SDRAM and DDR4 SDRAM. None of its successors are forward or backward compatible with DDR1 SDRAM, meaning DDR2, DDR3, and DDR4 memory modules will not work in DDR1-equipped motherboards, and vice versa.