Old Chestnut answer please...

[donslot]

Does anybody know who originally said 'When the going gets tough, the tough get going' ?

[Ethel]

Joseph P Kennedy, the father of John F Kennedy, is credited with this.

[charlie_h]

other interesting uses of the phrase are there:

It was the name of a Westlife(I Think anyway, don't quote me on that) song, the official song of a Comic Relief Day.

It was also used by raquel in an episode of Only fools and Horses.

[rja211077]

Billy Ocean did the original of the song.