The two Premier League clubs were charged earlier this week, and pleaded guilty, after Yannick Sagbo and Ashley Williams clashed during a Premier League game on December 9
The two Premier League clubs were charged by the FA earlier this week and have now been punished following a scuffle that broke out when the sides faced each other in a 1-1 draw at the Liberty Stadium on December 9.
Hull striker Yannick Sagbo and Swansea defender Ashley Williams clashed with around 10 minutes remaining in the game at the Liberty Stadium and a melee ensued.
A statement on the FA's official website on Wednesday said: "Swansea City and Hull City have both been fined £20,000 following a mass confrontation between the two sides.
"The clubs each admitted a charge of failing to ensure that its players conducted themselves in an orderly fashion.
"This follows an incident in the 80th minute of their fixture on December 9 2013."