Thérèse

[winkleberry]

Is it ridiculously old-fashioned?

(I'm french hence the spelling)

[Meteorite]

It's nice, and unusual :) Most people in the UK will get the accents wrong though.

[minipie]

Theresa is quite old fashioned but somehow the French version seems less old fashioned. I like it. Also, I'm a big fan of Tess or Tessa which are traditional nicknames for Theresa.

[ticktocktiptap]

A tad old fashioned I think.
Accents maybe stop it being - but people may not always include them, which maybe makes it ld fashioned once again.

[mathanxiety]

Lovely, and unusual these days.