What are the two yellow curves in McDonald's famous logo called?

The two yellow curves in McDonald's famous logo are called the Golden Arches.

The arches began as architectural features rather than an abstract logo. Architect Stanley Clark Meston designed them for a McDonald's restaurant in Phoenix, Arizona, in 1952. The tall yellow structures were intended to make the building visible from the road.

As McDonald's expanded, the arches became a recognizable symbol of the chain itself. The company later combined two arches into the familiar M-shaped emblem, turning an element of restaurant architecture into a global brand mark.

A common mix-up is calling the symbol simply the “yellow M.” McDonald's often uses that description informally, but Golden Arches is the established name associated with the branding and the architectural origin.