The Seal of Manila is composed of the city's modern coat-of-arms, with colors mirroring those of the Philippine National Flag.

The sea-lion originally represented the islands's former colonial status as an ultramar (overseas) possession of Spain, and is ultimately derived from the arms of the Kingdom of León.

For easier identification of the city, Manila was granted a coat of arms by a decree issued on 20 March 1596 by King Philip II of Spain.

And by this my decree, I charge the most serene prince, Don Philipo, my very dear and well beloved son, and the kings succeeding to me, and I order the infants, prelates, dukes, marqueses, counts, and grandees; the masters, priors, commanders and sub-commanders of the orders; the governors of castles, forts, and open districts; the members of my council, and the president and auditors of the same royal audiencias; the alcaldes, constables of my house, court, and chanceries; all the councils, corregidors, asistentes, governors, veinte e cuatros, regidors, and jurors; and the knights, squires, officials, and freemen of all the cities, towns, and villages of these my kingdoms and seigniories, and of my said Indias, islands, and Tierra Firme of the Ocean Sea–both in the present and future, and each and every one of them in his jurisdiction, who shall be notified of this–that they observe and regard, and cause to be observed and regarded the said grant of the said arms which I thus bestow upon the said city of Manila in the Filipinas Islands, so that they be allowed to place and possess them in the said city.

While the coat of arms evolved throughout the centuries, adopting different forms and minor changes, its basic elements remained much the same–a castle on red and a sea-lion on blue.

The motto, in gold was Timbulan ng Laya at Diwang Dakila (English:Buoy of Liberty and a Great Spirit).

The official website of the city government of Manila mentions the symbolism behind specific elements of the seal.