Periods (Full Stops) in Titles like Mr. and Mrs.

by Craig Shrives

The Quick Answer

Should you write "Mr Smith" or "Mr. Smith?
Should you write "Dr Jones" or "Dr. Jones?

If you're following US convention, put a period (full stop) after the title (known as a contraction). For example:
  • Mrs., Mr., Ms., Dr., Prof., Capt., Gen., Sen., Rev., Hon., St.
If you're following UK convention, you have a choice whether to use a period or not. Even though lots of Brits now follow the US style, most adhere to the following ruling:

If the last letter of a contraction is the same as the last letter of the whole word, then don't use a period. For example:
  • Mister > Mr correct tick
    • (The last letters are the same.)
  • Professor > Prof. correct tick
    • (The last letters are different.)
Here's a quirk: Don't use a period with "Miss" as it's not an abbreviation.
periods (full stops) in titles (Mr Mrs Dr Prof)

small American flag Periods in Titles

(For those following US conventions)

If you have a contraction that is a compressed version of a word (i.e., not the kind with an apostrophe like "can't," "isn't"), then put a period after it. For example:
  • Mr. (contraction of Mister) correct tick
  • Revd. (contraction of Reverend) correct tick
  • Rev. (also a contraction of Reverend) correct tick
  • para. (contraction of paragraph) correct tick
  • Dr. (contraction of Doctor) correct tick
  • The theory is supported by Prof. Munro and Mr Jones. wrong cross
    • (This should be "Mr. Jones" under US convention.)

small British flag Full Stops in Titles

(For those following UK conventions)

Brits are increasingly adopting the US convention. However, most still adhere to the following ruling: Only use a full stop (period) at the end of a contraction if its last letter is different from the last letter of the whole word. For example:
  • Mr (contraction of Mister) correct tick
  • Revd (contraction of Reverend) correct tick
  • Rev. (also a contraction of Reverend) correct tick
  • para. (contraction of paragraph) correct tick
  • paras (contraction of paragraphs) correct tick
  • Dr. (contraction of Doctor) wrong cross
    • (This is not wrong, but it doesn't follow the guideline being explained. As "r" is the last letter of "Dr" and "Doctor," there is no need for the full stop.)
  • para (contraction of paragraph) wrong cross
    • (A full stop is required under UK convention because the last letters of "para" and "paragraph" are different.)
  • The theory is supported by Prof. Munro and Mr Jones. correct tick
    • (As "r" is the last letter of "Mr" and "Mister," there is no need for the full stop. This would be wrong under US convention.)

Do You Use a Period with "Miss"?

Do not use a period with "Miss," which is not an abbreviation. For example:
  • I will attend with Prof. Plum and Miss Scarlet. correct tick
    • (This example fits both the US and UK conventions.)

Do You Use a Period with "Ms"?

A real oddity is the title "Ms," which isn't a word or an abbreviation. Americans should use a period. Brits shouldn't. They are the styles deemed least likely to annoy your readers:
  • I will attend with Prof. Plum and Ms. Scarlet. correct tick (small American flag)
  • I will attend with Prof. Plum and Ms Scarlet. correct tick (small British flag)
Read more about using "Miss" and "Ms."

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See Also

Using AD, BC, BCE and CE Ms., Miss, or Mrs.? Forming the plurals of abbreviations Writing abbreviations Using full stops (periods) in abbreviations What are acronyms? What are contractions?