The term nee is very common in family history and simply indicates the maiden name of a married woman.

If Mary WHITE married John WILSON I would record her as
Mary WILSON nee WHITE. (Mary WILSON maiden name WHITE)

Same as above nee is what the woman's surname was before marriage, so like Alice Jones married Peter Brown I would say Alice Brown nee Jones!
But in my family tree I have the female spouse's under their maiden names!

The term "née" is the feminine past participle of the French verb "naître" which means "to be born".

For a male it would be "né", but in genealogy it must be extremely rare for a man to change his surname on marriage. So, one could just as well write "born so-and-so" instead of "née", often abbreviated to just "b." in front of the maiden name or date of birth.

It looks as if this website cannot take accents, so please read "nee" or "ne"in my previous remarks. Also the verb cited is naitre, which normally has a circumflex over the letter i.
Incidentally, the circumflex indicates that in earlier times the letter covered by a circumflex would have been followed by an s (eg naistre). Another example would be maitre, derived from maistre, which in English subsequently gave us the word Master and Mister, as well as Mistress.

Née = nee
Naître = naitre
Né = ne

[admin note: the comment system has been updated so these special characters do now appear properly]

My original sir name was Skelton, but when my step father adopted me my name was changed to Wells, therefore for genealogy purposes I quote Wells (nee Skelton)

I see that Ken. I'll get that fixed and change them back!

I appreciate the proper explanations of the term nee as in earlier posts, but as I have been researching the family of my own parents and those of my husband for more than 50 years, we have found so many instances of a female who married a member of our family, who has remarried after the death of her husband that we use the term nee as also meaning "previously" - so a family member, for example, whose maiden name was Jones and she marries a Smith and he died, and she married again to a man name Black, is shown in our treef files as Black nee Smith nee Jones, and so far nobody in the family with whom we have shared our family history files appears to be confused as the which is the maiden name of the lady concerned. We of course also research details for that 2nd marriage as any children born in that marriage are half siblings of those from the first husband, who was in our direct line.

NEE - Well I never ever use or say the word and seldom ever write it down as I have done here. I see it written and it then gives me another approach at finding that person if I don't have a surname for them. That is the only time I have use for the word at all.

I was told to always put the females' born last name in ( ). Example. Mary Lee (TARLTON) SMITH. and that all last names in capital letters.

In Irish the word is rendered "ní" and pronounced the same as "nee" or "né." Although the etiology is somewhat different, (it is claimed to be short for 'nighean,' or 'inghean' in Scots-Gaelic, and in Irish means 'daughter') it means essentially the same, i.e. the daughter's original surname speaking patronymically. So (by way of an example) Carolyn O'Malley ní Sheppard would mean that the maiden surname of Carolyn was 'Sheppard.' Ní is sometimes spelled 'ni' in western cases where there is no easy access to the diacritic mark or "síneadh fada." Since westerners generally refuse to use the fada in any typed correspondence, 'nee' seems like a good compromise.

URLs reference:
https://en.wikipedia.org/wiki/Given_name#Name_at_birth
http://www.urbandictionary.com/define.php?term=nee
http://dictionary.reference.com/browse/nee
http://talkirish.com/forums/p/2294/3428.aspx
http://www.dwelly.info/
- Michael

Used to identify a woman by her maiden family name
If your maiden name were SMITH and your first husband is BROWN and your second husband is WHITE you are correctly referred to as Mrs. White, nee SMITH formerly BROWN. OR in some countries it is Mrs. White, nee Smith previously Brown.
@ Marysam -Working in research we write everything in capitals because there is less chance of transcription error.