The 28-year-old has joined on a two-month deal, and arrives following 11 appearances for the Cumbrians this season.
Born in Devon, Ellis started his career at Bolton Wanderers before making his senior debut whilst on loan at Torquay United in September 2007.
Having registered 24 appearances during the 2007-08 season, Ellis’ move to the Gulls was made permanent during the summer of 2008 where he then went on to make a further 112 appearances before moving to Crewe Alexandra in 2012 to join now O’s Head Coach Steve Davis.
The defender instantly became an integral part of what proved to be a successful year at Gresty Road, accumulating 52 appearances throughout the 2012-13 season as the Railwaymen lifted the Johnstone’s Paint Trophy at Wembley with a 2-0 victory over Southend.
Following a further year at Crewe, Ellis then made the switch to Shrewsbury Town, where he went on to spend two years and help achieve promotion from League Two in 2015 as Salop finished runners up.
During his time at Gay Meadow, the defender enjoyed two loan stints at Carlisle United before completing a permanent move in 2016.
Ellis also spent a period on loan at Forest Green Rovers last season, playing in their 3-1 Play-Off Final victory over Tranmere Rovers as the Green secured promotion from the National League.