The agency secured the £1.5 million account on a three-year contract after a pitch against EHS Brann, Tequila\ and the incumbent, Rapier.
Elvis will work with Digital UK until October 2012, which is when the final analogue signal switch-off is due.
The agency will devise campaigns that provide viewers with information on how to prepare for the switchover.
Elvis will work closely with Digital UK's ad agency, Abbott Mead Vickers BBDO, which has created campaigns featuring the character called Digit Al.
Digital UK is also in the process of holding a review of its digital business, which is currently held by Grand Union.