Mr Justice Moor said Scot Young, 51, from Dundee had been in "flagrant" contempt during a long-running High Court cash fight with Michelle Young, 48.
The judge described one explanation Mr Young had given for not complying with orders as "absurd" and said another response was "next to useless".
Today's hearing at the High Court in London was the latest stage in a legal fight stretching back several years.
High Court judges have heard that the Youngs, who both now live in London and have two daughters, separated in 2006.
In 2009, a judge ordered Mr Young to pay Mrs Young £27,500 a month maintenance.
Mr Young - who has been described at earlier court hearings as a "property tycoon" - says he is bankrupt and cannot pay.
Mrs Young says Mr Young has "secreted enormous assets".
Mr Young said he was "shocked" by the sentence and added - as he was led away in handcuffs and carrying a Louis Vuitton overnight bag: "This is a sad day for British justice."
Mrs Young disagreed and said: "What other choice do we have when someone is not complying with court orders, who is in contempt of court ... who is trying to leave me and my children destitute?"
Mr Young's girlfriend - model Noelle Reno, who said she celebrated her 29th birthday on Christmas Day - added: "It's not a great day, is it? I didn't expect six months."