Cable management systems for rotatable sensors on an autonomous vehicle (AV) are described herein. In some examples, a rotatable cable assembly can include a first portion having a spool, a sidewall surrounding the spool to form a cavity, and a shaft extending from the spool; a second portion coupled to the shaft and configured to rotate relative to the first portion; a flexible cable stored by the spool in a coiled configuration within the cavity; a first circuit on the first portion including a first connector coupled to an end of the flexible cable and configured to connect to components on an AV and/or a sensor platform base that is coupled to the AV and includes the rotary cable assembly; and a second circuit on the second portion including a second connector coupled to another end of the flexible cable and configured to rotate with the second portion.