In heraldry, the dolphin is a well established charge associated with the sea, swift movement, guidance, and noble energy. Its meaning draws partly from the long classical and medieval reputation of the dolphin as a creature friendly to humankind and closely linked with sailors, safe passage, and rescue. For that reason, a dolphin in arms often suggests protection in peril, success in maritime enterprise, loyalty, and graceful strength. It can also point to cheerful vitality and intelligence, since the animal was admired for both speed and seeming playfulness.

Heraldic artists, however, often depict the dolphin in a stylized form that looks quite different from the modern marine mammal. The traditional heraldic dolphin is commonly shown curved or embowed, sometimes upright or hauriant, and may resemble a decorative fish more than a natural creature. This older treatment gave the charge a bold silhouette that worked well on shields, seals, and civic arms. Dolphins appear in the heraldry of seafaring families and coastal towns, and they carry particularly strong historical associations with the Dauphins of Viennois and the province of Dauphiné, where the dolphin became an emblem of rank as well as maritime symbolism. In British heraldry, dolphins also appear in the arms or crests of several families, especially those with naval, coastal, or fishery connections.

For reliable heraldic background, see Dolphin (heraldry) on Wikipedia, which gives a concise overview of posture and history, and John Vinycomb’s classic discussion of the figure in Fictitious and Symbolic Creatures in Art. For visual examples, the best starting point is Wikimedia Commons: Dolphins in heraldry, along with the illustrated forms at Traceable Heraldic Art: Dolphin. Taken together, these sources support the dolphin as a heraldic emblem of maritime mastery, protection, noble service, and confident motion.