Dawn (from an Old English verb dagian "to become day") is the time that marks the beginning of the twilight before sunrise. It is recognized by the presence of weak sunlight, while the sun itself is still below the horizon. Dawn should not be confused with sunrise, which is the moment when the leading edge of the sun itself appears above the horizon.

The duration of the twilight period between dawn and sunrise varies greatly depending on the observer's latitude, from a few minutes in equatorial regions to many hours in polar regions.

There are also more technical definitions of dawn, including the following:

During dawn (and dusk) it is usually possible (provided that the sky is cloud-free) to see approximately in which direction the sun is (though it's below the horizon). Though it is possible to localize the direction of the sun during astronomical dawn and dusk, people in general experience astronomical dawn and dusk as night, even without clouds. Zenith is dark and more than just the brightest shining stars can be seen (except low above the horizon in the direction of the sun).