Other contributors have said "Who said this you can fool some people some time but you can not fool all the of people all the time?" is the same question as "Who said 'You can fool all the people some of the time and some of the people all the time but you cannot fool all the people all the time'?". If you believe that these are not asking the same thing and should be answered differently, click here.
Who said 'You can fool all the people some of the time and some of the people all the time but you cannot fool all the people all the time'?
Answer:
It is commonly attributed to Abraham Lincoln, but there appears to be no hard evidence that he actually said it. It has also been attributed to P. T. Barnum (of the world famous Ringling Bros. Barnum and Bailey Circus), poet John Lydgate and Mark Twain.
There is also a variant (sometimes claimed to be the original form):
"You can please some of the people all of the time, you can please all of the people some of the time, but you can't please all of the people all of the time."