The man died as he was being taken to hospital by his family. He was said to have suffered a night of severe vomiting.
Several other members of the same family, including a toddler and an elder brother of the deceased, have been admitted to different medical facilities around Nairobi, where they are receiving treatment for cholera.
It is feared that the infection could spread to other parts of the country since more people had travelled to attend the wedding ceremony that was held on grounds near the Karen Country Club.
Bernard Muia, the Nairobi County executive member for health, was hesitant to indicate whether the death was linked to cholera.
"We can only confirm it is cholera after results of the postmortem are released," Muia said, but indicated that he had been briefed about Saturday's wedding ceremony.
None of the victims was able to speak to us as they were reported to have been quarantined, as is the norm when a contagious disease is involved.
Information suggests that the food consumed at the ceremony was prepared elsewhere and brought to the venue known to host expensive weddings.
Food samples for testing
Health officials from the county were unable to retrieve any food samples for testing, because "they ate it all", Muia told The Standard.
He added that the caterers had defied a directive banning off-site food handling, which was blamed for the last cholera outbreak that caused several deaths around the country.
"The ban on outside catering has never been lifted," Muia said, citing the cholera situation that has until now been under control.
News about the outbreak and the death may not come as a surprise, considering that the high-end Karen neighbourhood would be ground zero of the infection for the second time.
Several deaths were reported in May for people, including foreigners, who had attended a wedding in the same place.