A post is a moderate to deep passing route in American football in which a receiver runs 10–20 yards from the line of scrimmage straight down the field, then cuts toward the middle of the field (towards the facing goalposts, hence the name) at a 45-degree angle.
It is designed to stretch the opposing secondary deep down the field, opening holes in the coverage over the middle. It works particularly well against secondaries that don't have more than one safety who is effective in coverage, or against safeties with 2 or 4 deep zone players, attacking the void in the middle of the field. It tends to induce the opposing defense to play a deeper field and drop more defenders into deep coverage, but this may still open up the run. Cover 3 packages can be effective against it, if the defender in middle deep coverage is perceptive enough.
To run the route effectively, a wide receiver must be adept at catching the ball in traffic, and have the vertical ability and strength to rise above the top of a safety to catch the ball.
A variant of the post pattern, in which the receiver cuts infield at a shallower angle, is called a skinny post. It is designed to find a hole in deep coverage, cutting shallow inside the deep sideline defender, but not far enough to draw the middle defender.