Heather Mills claims to have received the largest media libel settlement in the UK's "legal history" after settling a phone-hacking case against News of the World.
The businesswoman and ex-wife of Sir Paul McCartney settled her claim against News Group Newspapers (NGN) in February for an undisclosed sum.
Today, an apology from NGN was read out to Ms Mills and her sister Fiona Mills - whose claim was also settled - at the High Court.
Ben Silverstone, for NGN, said: "The defendant is here today, through me, to offer its sincere apologies to Ms Heather Mills and Ms Fiona Mills for the distress caused to them by the invasion of their privacy by individuals working for or on behalf of the News of the World.
"The defendant accepts that such activity should never have taken place and that it had no right to intrude into the private lives of Ms Heather Mills or Fiona Mills in this way."
Ms Mills told reporters she felt "joy" and "vindication" after settling the case, which related to "invasion of privacy" between 1999 and 2010.
"My motivation to win this decade-long fight stemmed from a desire to obtain justice, not only for my family, my charities and myself, but for the thousands of innocent members of the public who, like me, have suffered similar ignominious, criminal treatment at the hands of one of the world's most powerful media groups," she said.
She added that phone-hacking had "an extremely detrimental impact" on her life.
When asked if this was the end of her litigation against NGN, she replied: "This is the end for now - unless anything else pops up."