The traditional ceremony took place in Dorchester Abbey, in Oxfordshire, and joining the British royals were Ben Fogle and his wife, Marina.
Eugenie, wore a charcoal dress with a wool coat and fascinator.
Jamie is a close friend of Harry and the Duke and Duchess of Cambridge's and owns the multi-million pound online business, Glasses Direct, while Lottie is a successful barrister.
The jovial celebrations come just over a week after Harry returned to the UK following a quiet trip to Lesotho as part of his on-going work with his charity, Sentebale. The Prince's visit was timed to see the construction of the new Mamohato Children's Centre, which will support local children living with HIV, by providing them with healthcare and education.
Whilst there Harry took several personal photos which he then released publicly, revealing: "I have always enjoyed photography and the challenges that come with trying to capture the perfect shot, although privately I don't take many photos.
"The best photos I have are in my head – I have some very special memories, mostly from Africa.
"But on this visit, I had the time and opportunity to be on the other side of the camera and take some photos in the stunning country of Lesotho for my charity Sentebale."