Yttrium (Y) is a chemical element with atomic number 39. Its only stable and naturally occurring isotope is ⁸⁹Y, with 39 protons and 50 neutrons.

Yttrium has a variety of applications. For example it is used for certain color components in CRT TVs and LED lights, and also as an ingredient in certain cancer treatment drugs. It is sometimes also used in alloys to strengthen other metals like aluminium.