The Coat of Arms of Warsaw consists of a syrenka in a red field. Polish syrenka is often rendered siren, but she is more properly a fresh-water mermaid called a “melusina.”

Initially the Coat of Arms of Warsaw depicted a dragon with human male's head, carrying a sword and a shield. The first known usage was on a stamp from 1390. Gradually the male head and corpse was replaced with that of a female and by the end of 16th century. The tail was also changed from that of a dragon to that of a fish and the only remaining part of the original Coat of Arms are sword and shield.

Since 1622, the Warsaw Coat of Arms has been rendered as a mermaid with sword and shield in hand, representing the melusina from the River Vistula (Wisła), who in legend led Duke Boleslaus of Mazovia to the appropriate site (a fishing village) and ordered him to found the city, in about 1294. The city’s motto is, appropriately, Contemnit procellas (“It defies the storms”).

This project has been introduced as the city’s Coat of arms in 1938 and was used as an official emblem only until World War II broke out. After 1945 Communist authorities changed the emblem — the crown was cut out. It was re-introduced on August 15, 1990 in it’s original form. Currently the city authorities are considering to add the Virtuti Militari medal symbol to the emblem to underline the merits of Warsaw during the Battle of Warsaw and World War II. It is also planned to add the other city's motto to the emblem - Semper invicta (Always invincible).