Technically, the song phrase is based off of the Italian phrase "quello che sarà, sarà". This means "what will be, will be." Still an unfortunate name, but the description listed with the name isn't quite right.
The phrase "Que sera, sera" was an alteration of a quasi-Italian phrase, "Che sara, sara," a fictional family motto in the 1954 film The Barefoot Contessa. It is not Spanish, Italian, or French (but is acceptable in spoken Portuguese). The correct Spanish, Italian, French and Portuguese renderings of the phrase are: Portuguese: O que será, será Spanish: Lo que será, será Italian: Quello che sarà, sarà French: Ce qui sera, sera. [noted -ed]Information found at Wikipedia.org (support the wiki!)
Sorry, my mistake. Just found out recently that "que sera, sera" IS French for "what will be, will be". "Sera" is the future tense of "etre", apparently, in the il/elle/on form. (awkward cough)