Radical 72 or radical sun (日部) meaning "sun" or "day" is one of the 34 Kangxi radicals (214 radicals in total) composed of 4 strokes.

In the Kangxi Dictionary, there are 453 characters (out of 49,030) to be found under this radical.

日 is also the 75th indexing component in the Table of Indexing Chinese Character Components predominantly adopted by Simplified Chinese dictionaries published in mainland China, with 曰 (formerly Kangxi Radical 73 "say") and ⺜ being its associated indexing components.

The radical is also used as an independent Chinese character.

It is one of the kyōiku kanji or kanji taught in elementary school in Japan.