Ytterbium (Yb) is a chemical element with atomic number 70. Just like yttrium, erbium and terbium, it is named after the Swedish village Ytterby, where it was first discovered.

The most abundant ytterbium isotope is ¹⁷⁴Yb, with 70 protons and 104 neutrons.

Ytterbium has several noteworthy applications, such as X-ray machines, atomic clocks, and possibly future quantum computers.