The 52-year-old filmmaker, writer and producer married the 62-year-old financier on September 12. Sharing a series of photographs on Instagram, Jemima thanked the family and friends who helped make the occasion special.
The wedding also brought together members of Jemima's family from her previous marriage to Khan.
Sulaiman, Kasim walk Jemima down the aisle
Jemima revealed that her sons, Sulaiman and Kasim Khan, whom she shares with Imran Khan, walked her down the aisle.
Photo: Instagram/Jemima Goldsmith
She also thanked her stepdaughter, Tyrian White, for serving as her maid of honour.
Cameron's daughters, Sasha and Tara O'Reilly, were among the bridesmaids, alongside Edie and Eliza. The wedding party also included Bluey and Arthur as pageboys.
Cameron's sons, Elliot and Oscar O'Reilly, served as his best men.
Jemima's nephews Frankie, Isaac and James Goldsmith, along with Cameron's brothers Gavin and Tony O'Reilly, were among the ushers.
Jemima's Oscar de la Renta wedding dress
For the ceremony, Jemima wore a custom Oscar de la Renta gown.
The strapless, tea-length white dress featured horizontal detailing, sheer tulle and a floral applique at the waist.
She completed the look with a long pearl-covered veil and wore her hair in soft waves.
In photographs from the celebrations, Jemima and Cameron are seen posing with family and friends. The reception featured a wedding cake decorated with fresh figs and berries.
Jemima later changed into a white mini dress with pleated shoulders.
Photo: Instagram/Jemima Goldsmith
She also credited stylist Martha Ward for helping with her wedding looks and thanked Kate Rothschild and Annabel Rivkin, describing them as part of her "A team" during the preparations.
Jemima, Cameron were together for over a year
Jemima and Cameron had reportedly been in a relationship for more than a year before their wedding.
The marriage was first reported earlier this week, before Jemima herself confirmed the news by sharing photographs from the ceremony on Instagram.
Cameron O'Reilly is the son of late Irish-Australian media businessman Sir Anthony O'Reilly.
He previously worked in his father's media businesses before founding private equity firm Bayard Capital.
Jemima's marriage to Imran Khan
Jemima was previously married to Imran Khan. The couple tied the knot in 1995 when Jemima was 21 and later moved to Pakistan.
They divorced in 2004 after nine years of marriage and have two sons, Sulaiman and Kasim.
Jemima has remained publicly supportive of her sons and has occasionally spoken about her former marriage and life in Pakistan.
Her wedding to Cameron marks her second marriage.