Kim Kardashian to Olivia Wilde: Biggest Celebrity Breakups of 2011 [PHOTOS]

The year 2011 has not been great for celebrity romance. High-profile breakups were the order of the year, from Kim Kardashian and Kris Humphries to Olivia Wilde and Tao Ruspoli to Arnold Schwarzenegger and Maria Shriver.

Divorces were finalized, separations initiated, puppy-love relationships ended, on-and-off relationships did what they always do, and at least one wedding was called off.

Here are photos of some of the biggest celebrity splits of 2011.

Kim Kardashian

Jennifer Lopez and Marc Anthony

There are allegations that Kutcher cheated, hence Moore's recent announcement, but People magazine reported that the relationship had already been tense.

Arnold Schwarzenegger and Maria Shriver split up after more than 20 years of marriage when it was discovered he had fathered a son with their housekeeper several years earlier.

Olivia Wilde and Tao Ruspoli got married in 2003 when she was 19 -- and split this year. Wilde has defended Kim Kardashian after Kardashian filed for divorce. "No one should be attacking her," Wilde told the New York Post. "Our attention should be focused on things that are truly scandalous."

Derek Jeter and Minka Kelly split in August, but the New York Post reported in October that Jeter had gone down to Miami to see Kelly, who was in town filming "Charlie's Angels."

Often featured in People magazine's "Sexiest Man Alive" issue, actor and activist George Clooney and Italian model Elisabetta Canalis were dating from June 2009 until June 2011, when Clooney and Canalis released a statement to US Weekly saying that they were no longer together.

The UK's Daily Mail reported that Loudon could not bear the media "circus" around Middleton, younger sister to Catherine, the Duchess of Cambridge.

Playboy founder, Hugh Hefner, and Playmate for the month of December 2009, Crystal Harris, got engaged in Dec. 2010.
Harris met Hefner, 85, on Halloween 2008. In January 2009, the couple started dating, after his previous girlfriend, Holly Madison, left him. The couple had planned the wedding for June 2011, but five days before the wedding, Harris, 25, broke off the engagement on June 14, 2011.

Ashlee Simpson filed for divorce from Wentz in February. They have a son together, Bronx Mowgli.

On-and-off couple Sienna Miller and Jude Law reportedly split up earlier this year.

Glee honey Dianna Agron and "In Time" actor Alex Pettyfer split up in February.

Christina Aguilera's divorce from Jordan Bratman was finalized this year. They met in 2002 and got married in 2005.

Charlie Sheen and Brooke Mueller's divorce was finalized this year after a tumultuous marriage.

Eva Longoria told Extra's Mario Lopez that she found text messages from another woman on Parker's cell phone.

Tareq Salahi crashed the White House, but does he have a chance at the governor’s mansion in Virginia?