Know the facts – Who designed the Olympic rings?

The founder of the International Olympic Committee (IOC), Pierre de Coubertin, created the Olympic rings in 1913. He drew and coloured the rings by hand at top of a letter written.  
In the Olympic Review of August 1913, he explained that "These five rings represent the five parts of the world now won over to Olympism and ready to accept its fertile rivalries. Moreover, the six colours thus combined reproduce those of all the nations without exception."

Based on a design first created by Coubertin, known as the father of modern Olympic Games, the Olympic rings remain a global representation of the Olympic Movement and its activity.

“The Olympic symbol consists of five interlaced rings of equal dimensions (the Olympic rings), used alone, in one or in five different colours. When used in its five-colour version, these colours shall be, from left to right, blue, yellow, black, green and red. The rings are interlaced from left to right; the blue, black and red rings are situated at the top, the yellow and green rings at the bottom in accordance with the following graphic reproduction.” (Olympic Charter, Rule 8)

1913 – Introduction of the Olympic rings - The Olympic rings were publicly presented for the first time in 1913. In the centre of a white background, five rings interlaced: blue, yellow, black, green and red.

1920: The official Olympic Games debut of the Olympic rings- For the Olympic Games, the Olympic rings, set on the white background of the Olympic flag, made their first appearance at the Games of the VII Olympiad Antwerp 1920.

Inputs from Olympic website, Wikipedia, other online sources