Vdersolstavlan (pronunciation ; Swedish for 'The Sundog Painting') is an oil-on-panel painting depicting a halo display, an atmospheric optical phenomenon, observed over Stockholm on 20 April 1535. It is named after the sun dogs (Swedish: Vdersol, lit.'weather sun') appearing on the upper right part of the painting. While chiefly noted for being the oldest depiction of Stockholm in colour, it is arguably also the oldest Swedish landscape painting and the oldest depiction of sun dogs.

The original painting, which was produced shortly after the event and traditionally attributed to Urban mlare ("Urban [the] Painter"), is lost, and virtually nothing is known about it. However, a copy from 1636 by Jacob Heinrich Elbfas held in Storkyrkan in Stockholm is believed to be an accurate copy and was until recently erroneously thought to be the restored original. It was previously covered by layers of brownish varnish, and the image was hardly discernible until carefully restored and thoroughly documented in 19981999.

The painting was produced during an important time in Swedish history. The establishment of modern Sweden coincided with the introduction of Protestantism and the break-up with Denmark and the Kalmar Union. The painting was commissioned by the Swedish reformer Olaus Petri, and the resulting controversies between him and King Gustav Vasa and the historical context remained a well-kept secret for centuries. During the 20th century the painting became an icon for the history of Stockholm and it is now frequently displayed whenever the history of the city is commemorated.

A sun dog (or sundog) or mock sun, also called a parhelion (plural parhelia) in meteorology, is an atmospheric optical phenomenon that consists of a bright spot to one or both sides of the Sun. Two sun dogs often flank the Sun within a 22° halo.

The sun dog is a member of the family of halos caused by the refraction of sunlight by ice crystals in the atmosphere. Sun dogs typically appear as a pair of subtly colored patches of light, around 22° to the left and right of the Sun, and at the same altitude above the horizon as the Sun. They can be seen anywhere in the world during any season, but are not always obvious or bright. Sun dogs are best seen and most conspicuous when the Sun is near the horizon.