There are just some things you are guaranteed to reference when writing about a university or on an education beat.
I wrote last week about how to write academic degrees. This post is on the related subject of referencing academic departments.
Use lowercase when writing about academic degrees, except when using words that are proper nouns or adjectives.
For example, I work in the department of mass communications. We have a lot of fun in the mass communications department. She teaches in the department of English, which also is fun.
Capitalized the department name only when it is the full, official, formal name.
For example, I work in Fake University’s Department of Mass Communications.
It seems, according to AP Style, that you do not capitalize “department” unless you include the university name as well. I see this done incorrectly a lot, but the overall rule is pretty simple.
Now go forth and use words correctly!