Harris, 26, kept fans updated about her big day with her posts on Twitter, reports femalefirst.co.uk.
"Today is the day I become Mrs. Hugh Hefner. Feeling very happy, lucky, and blessed," she posted.
She also uploaded a picture of staffers setting up the altar, alongside a caption which read, "The mansion is looking beautiful #weddingbells".
Hefner and Harris were originally set to walk down the aisle in June 2011, but the model-turned-lingerie store owner got cold feet and called off the wedding.
They reconciled in May 2012 and Hefner proposed to Harris again in December 2012. Hefner announced he was planning to ring in 2013 as a married man.
This is Hefner's third marriage. He was married to Mildred Williams from 1949 to 1959 and wed Kimberley Conrad in 1989. The couple divorced in 2010.