It is named after the physicist and engineer William Thomson, who became Lord Kelvin when he was made a peer.
The kelvin as an SI unit is correctly written with a lowercase k (unless at the beginning of a sentence), and is never preceded by the words degree or degrees, or the symbol °, like Fahrenheit, or Celsius. This is because the latter are scales of measurement, whereas the kelvin is a unit of measurement. Note that the symbol for a kelvin is always a capital K.
