Formation L was a marching order used by the crew of the USS Enterprise in the late 2260s for landing parties on the move through hostile, or potentially hostile, territory. The order instructed the party to form a column with phasers held at the ready. A security officer took the point, followed by officers and crew in descending order of rank, with the junior officer bringing up the rear.

In 2267, Kirk ordered a landing party on Gamma Trianguli VI to use this formation following Hendorff's death and the realization that they were being followed by someone. (TOS: "The Apple")