The Willow Pattern is a gong'an detective novel written by Robert van Gulik and set in Imperial China (roughly speaking the Tang dynasty).

It is a fiction based on the real character of Judge Dee (Ti Jen-chieh or Di Renjie), a magistrate and statesman of the Tang court, who lived roughly 630–700.

"The opening scene carries out the in medias res advice: a beautiful young girl in dishabille is arranging an old man's corpse to look like accidental death.

The next brings on Judge Dee, in his usual philosophizing mood and flanked by the faithful Chiao Tai as they discuss the plague-stricken, half-deserted city.

In the heat of summer, Dee has to discover the motive and agent of three murders, each separate but also related.