The 51st Signal Battalion is a United States Army unit which is part of the 22d Corps Signal Brigade located at Joint Base Lewis–McChord, Washington. Its mission is to rapidly deploy worldwide to engineer, install, operate, maintain, and defend the LandWarNet in support of full spectrum operations. The battalion deployed to Iraq in 2003 – 2004 and in 2008 – 2009 and sent elements to Afghanistan in 2010 and 2011. The unit was deployed as of January 2015, and 2019.