To further elaborate (since I did this for the first time recently), my fellow monks are correct that
DBD::Oracle is the module you want. In order to install it, however, you must already have set up a full Oracle client installation, including specifically the OCI (Oracle Call Interface) drivers for your platform. You also need to set the $ORACLE_HOME environment variable before trying to even install
DBD::Oracle. This tripped me up initially because I had worked with Java on Oracle before, and in Java you have a choice of using OCI or the "thin" driver, which is pure Java and requires no ORACLE_HOME. But there is no pure Perl driver for Oracle, AFAIK.