It seems this song began its life with the title WHEN THE SUN SAYS GOODNIGHT TO THE MOUNTAIN. The words (in English) were written by Harry Pease, and the music by Larry Vincent, in 1936. There was an early recording by the British dance band Geraldo and his Gaucho Tango Orchestra, with vocalist Monte Rey. (Google gives 70+ hits with this title.)

In French, it was known as QUAND LE SOLEIL DIT BONJOUR AUX MONTAGNES. The French lyrics were apparently written by Annette and Carmen Richer. There was an early recording by Lévis Bouliane and Aurèle Lacroix; a more recent one by Carole Laure. I suspect there are many more. (Google gives 600+ hits on this title.)

It has only been known as THE FRENCH SONG since Lucille Starr recorded it with that title in 1964. Under that title, it has also been recorded by Stompin' Tom Connors, Jimmy C. Newman, and The Sandpipers.