The following did have male hosts to dances with female passengers, worth checking when you book Silversea, Regent Seven Seas, Holland America, Cunard. Crystal Cruises and I have seen them on some Celebrity ships but no sign on the last ship we were on called the Mercury but may be available on Millenium or some of the others, worth checking out with a travel agent.
Fred. Olsen always have hosts. They make quite a lot of ballroom dancing on thie cruises with lessons from professionals as part of the programme. Their Christmas / New Year cruises are a good blend of the traditional festivities with the normal pleasures of cruising. Many of these cruises have the added advantage of sailing from UK ports including Dover and Southampton.
I totally endorse the comments of 'Miller'. Fred Olsen ships always have male dance hosts to ensure single ladies are not without a dance partner. On my last four cruises with the company there was also a professional couple who gave group lessons. Good fun! Saga ships also have hosts. If you're not in the more mature age group and to be fair Fred Olsen and Saga ships do attract an older age group, try Cunard. Recent cruises on Queen Victoria and QM2 had dance hosts and a professional dance couple. The male dance hosts I met, apart from one guy, were all American and I didn't find they were particularly good dancers. It depends on your proficiency on the dance floor! Happy cruising - Jan .