Blues chief executive Richard Holland said in a club statement: "The Cardiff Blues management have discussed the matter at length but have acted swiftly since the incident occurred on Saturday morning.
"Gavin admitted himself that his behaviour was totally unacceptable and the immediate termination of his contract sends out a clear message that behaviour like that will not be tolerated at the Blues.
"We have a duty to our supporters and sponsors to protect the good name of Cardiff Blues and those associated with our brand.
"Gavin Henson is obviously a talented rugby player and it's unfortunate that his career at the Blues has ended this way."
The mid-flight incident which triggered his sacking is one in a long line of controversies.
Wales rugby star Gavin Henson has been suspended by his club following an incident on a plane.