What punctuation should I put before a quote?

[Marmitetoasties]

I'm finishing my MA thesis (history) just proofreading and I've realised I've been putting ; before a quote such as

Mr Academic says;

"................"

Blah blah blah

Is this correct? I've got a feeling its not.

I'd use a comma.

@onlyconnect thanks, is this the same when its a long indented quote in the text?

With a comma. Though I would be inclined to say, According to Mr Academic ".........."

If you want to do it properly then it depends whether it is an independent clause.

www.grammar-monster.com/lessons/quotation_(speech)_marks_colon_or_comma.htm

Mr Academic said, "SpicyTomatos, you are the best!"
Mr Academic was particularly impressed with SpicyTomatos: "SpicyTomatos is the best student I have had."

In particular, Ms Academic noted that "orange juice and toothpaste taste vile together." (followed by either a footnote reference or an in-text citation)

If the quotation is longer than three lines long, you separate the quote from the body by a line fore and aft, leave off the quotation marks, and indent it by half an inch, preceded by

Ms Academic noted that:

[indent block quote] blah blah blah for more than three lines followed by aforementioned footnote or in-text citation.

I need to get a life!

FYI you only need a comma in the first place if it would be used in the sentence anyway.

Oh, and don't ever put your quotations in italics

Quotation.

Avoid semicolons if you don't know how to use them (not just in relation to quotations, but also in general).

Check whether your faculty has a style guide. If you're lucky some nice person will have given you worked examples of all of this somewhere.