But announcing his decision on the settlement yesterday, Judge Martin O'Dwyer said parts of the case could now be made public.
He dismissed Gallagher's claims that former All Saints star Miss Appleton had indulged in 'wanton expenditure' or 'a revenge spending spree' after they broke up. Judge O'Dwyer said she was simply spending what she had become accustomed to as the wife of a rock star. He said that Gallagher had told his wife by phone about his affair 'when publicity was going to occur'. And he accused Gallagher, who fronted Beady Eye after the break-up of Oasis, of underestimating his earnings potential.
The singer told the court he had 'no prospect' of re-entering the music business.
Although he would like to reform Oasis with his older brother Noel, he did not expect it to happen.
Much of his earnings now come from his clothing company Pretty Green and royalties from Oasis. Judge O'Dwyer said Gallagher had 'clearly downplayed' his income and suggested that he should take part in 'celebrity appearances' to boost his finances.
The judge also rejected Gallagher's claims that his ex-wife had been unwilling to get a job. Miss Appleton had argued she was keen to find work, but that having been in the music business since leaving school she was unqualified and lacked the training and experience required by many employers.
Gallagher's legal team suggested that she could find a job in a shop or harness her celebrity status to make cash. Miss Appleton told the court that her music career had 'effectively been on hold for many years' and that, despite a recent attempt to revive it, she 'does not know what the future holds'.
The judge criticised the couple over the amount they had spent on lawyers.
'The level of costs in this case, totalling over £800,000, are manifestly excessive for the determination of the dispute, which involves capital sums not much greater than £10million,' he said. Gallagher hired top divorce lawyer Fiona Shackleton. Baroness Shackleton represented Prince Charles in his divorce from Princess Diana in 1996 and Sir Paul McCartney in his 2008 divorce from Heather Mills - during which Miss Mills threw a glass of water over her.
Miss Appleton was represented by Raymond Tooth, known for backing celebrity wives in high-profile divorce cases. His previous clients have included actress Sadie Frost and Irina Abramovich, ex-wife of billionaire Chelsea owner Roman Abramovich.
Awarding Miss Appleton £5.4million, Judge O'Dwyer said that if Gallagher's music career takes off again, she can return to court to seek a review.
She was Gallagher's second wife. He married actress Patsy Kensit in 1997.
Months after the wedding, Gallagher had an affair with Lisa Moorish which resulted in the birth in 1998 of a daughter, Molly.
He has a son, Lennon, born in 1999, with Miss Kensit. They were divorced in 2000, the year he began his relationship with Miss Appleton.
