Louis William Tordella (May 1, 1911 – January 9, 1996) was the longest serving deputy director of the National Security Agency.

He joined the US Navy, immediately made contacts in the service, and was brought aboard as a lieutenant junior grade in 1942.

After the war Tordella stayed on with the Navy, and in 1949 joined the newly created Armed Forces Security Agency (AFSA), an early attempt to achieve service unity in the business of cryptology.

His grasp of computer technology and the associated engineering concepts, coupled with his understanding of cryptanalysis, led Tordella to push forcefully for the development of supercomputers for cryptologic applications.

Close collaborators in Britain and the Commonwealth of Nations built up such a trust with Tordella that many foreign intelligence officials regarded him as the linchpin in their relationship with NSA.

According to Stephen Budiansky, "...the documents turned out to be a compendium of every single one of NSA's most highly classified, compartmented programs of the post-World War II era."