Los Alamos usually refers to the United States national laboratory in Los Alamos, New Mexico which was founded during the World War II effort to develop the atomic bomb (the Manhattan Project), was one of the two laboratories developing the USA's nuclear weapons during the Cold War, and is today a major laboratory for both classified and unclassified scientific research:

• Los Alamos National Laboratory

It is also the name of a number of geographical locations in the USA:

• Los Alamos, California
• Los Alamos, New Mexico
• Los Alamos County, New Mexico

At least one ship also carried the name:

• Los Alamos (AFDB-7) was a large floating dry dock.