Ununoctium, with 118 protons, has the highest number of protons, but uranium has the most protons of any naturally occurring element with 92. However, ununoctium is a manmade element, as it isn't possible for it to exist in nature.
Uranium is the heaviest natural element. In addition to ununoctium, which was first discovered by a team of Russian chemists in 2006, there are 25 other manmade elements that have more protons and are heavier than uranium.
The discovery of ununoctium was made through the collision of light particles, which resulted in an atom of ununoctium that lasted for less than one-thousandth of a second before breaking apart.