In Homer's the Odyssey, Argos (Ancient Greek: Ἄργος) is Odysseus' faithful dog. After twenty years struggling to get home to Ithaca, Odysseus finally arrives at his homeland. In his absence, reckless suitors have taken over his house in hopes of marrying his wife Penelope. In order to secretly re-enter his house to ultimately spring a surprise attack on the suitors, Odysseus disguises himself as a beggar, and only his son Telemachus is told of his true identity. As Odysseus approaches his home, he finds Argos lying neglected on a pile of cow manure, infested with lice, old and very tired. This is a sharp contrast to the dog Odysseus left behind; Argos used to be known for his speed and strength and his superior tracking skills. Unlike everyone else, including Eumaeus, a lifelong friend, Argos recognizes Odysseus at once and he has just enough strength to drop his ears and wag his tail but cannot get up to greet his master. Unable to greet his beloved dog, as this would betray who he really was, Odysseus passes by (but not without shedding a tear) and enters his hall, and Argos dies. The simplicity of the relationship between Argos and Odysseus allows their reunion to be immediate and sincere.

Argos (Greek: Ἄργος, Árgos, [ˈarɣos]) is a city and a former municipality in Argolis, Peloponnese, Greece. Since the 2011 local government reform it is part of the municipality Argos-Mykines, of which it is a municipal unit. It is 11 kilometres from Nafplion, which was its historic harbour. A settlement of great antiquity, Argos has been continuously inhabited for the past 7,000 years, making it one of the oldest cities in Greece and Europe. The city is a member of the Most Ancient European Towns Network. At a strategic location on the fertile plain of Argolis, Argos was a major stronghold during the Mycenaean era. In classical times Argos was a powerful rival of Sparta for dominance over the Peloponnese, but was eventually shunned by other Greek city-states after remaining neutral during the Greco-Persian Wars. Numerous ancient monuments can be found in the city today, the most famous of which is the renowned Heraion of Argos, though agriculture (particularly citrus production) is the mainstay of the local economy.

The domestic dog (Canis lupus familiaris), is a subspecies of the gray wolf (Canis lupus), a member of the Canidae family of the mammilian order Carnivora. The term "domestic dog" is generally used for both domesticated and feral varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in human history. The word "dog" may also mean the male of a canine species, as opposed to the word "bitch" for the female of the species.

The present lineage of dogs was domesticated from gray wolves about 15,000 years ago. Remains of domesticated dogs have been found in Siberia and Belgium from about 33,000 years ago. None of these early domestication lineages seem to have survived the Last Glacial Maximum. Although mDNA suggest a split between dogs and wolves around 100,000 years ago no specimens predate 33,000 years ago that are clearly morphologically domesticated dog.

Dogs' value to early human hunter-gatherers led to them quickly becoming ubiquitous across world cultures. Dogs perform many roles for people, such as hunting, herding, pulling loads, protection, assisting police and military, companionship, and, more recently, aiding handicapped individuals. This impact on human society has given them the nickname "Man's Best Friend" in the Western world. In some cultures, dogs are also source of meat. In 2001, there were estimated to be 400 million dogs in the world.