Alan Steele, a 58-year-old lorry driver from Tettenhall, posted on Facebook this morning saying he was being taken to hospital from the cruise ship which is quarantined off Yokohama Bay in Japan.
Mr Steele said: "Just to let you all know I have been diagnosed as having the virus and am being shipped to hospital.
"Would also like to say that at the moment I am not showing any symptoms so just possible a carrier.
"Will let you know how I am going on when possible."
Mr Steele had recently moved to Tettenhall with his new wife Wendy after the couple got married in Little Drayton, Shropshire, where Mr Steele is from.
Wendy, a 51-year-old mental health nurse from Tettenhall, is still on board the ship, while Mr Steele's son Damien said today that he was yet to speak to his father but knew that he had been taken to hospital.
Damien said he had learnt the news this morning and had only received a few text messages in addition to the information on Facebook.
Alan and Wendy got married at Christ Church, Little Drayton, on January 11 before heading to Tokyo to start their honeymoon. The vicar who conducted the ceremony today revealed the couple had brought their wedding forward in order to travel on the Diamond Princess.
Mr Steele had been posting about the situation regularly on Facebook after finding out on Tuesday that everyone on board the ship would be quarantined for 14 days.
He criticised the lack of information being provided and said on Wednesday "we are now only fed sandwiches as and when they feel like feeding us and we are in solitary confinement".
Yesterday Mr Steele said the food situation had slightly improved and that he and his wife were killing time watching films they had already seen before he revealed at 6am today that he had tested positive.
Fellow passenger David Abel said in a video update posted on Facebook that he had been dining with Mr Steele.
He added: "He will almost certainly be leaving the ship today - real, real shame.
"I have no idea how he must be feeling ... they're on their honeymoon.
"He will be going off in to quarantine in a medical facility and she has to stay on board the ship because she's not displaying symptoms.
"That's going to be really, really tough for him so just bear a thought for these passengers who just don't know what is going to be lying ahead of them."
Princess Cruises said 41 people had tested positive for the virus on the Diamond Princess.
The announcement comes after a third person in the UK was diagnosed with coronavirus, and is believed to have caught the illness in Singapore.
It has been reported that this third patient is a middle-aged British man who is understood to be the first UK national to contract the disease.
Princess Cruises said the quarantine on the ship was due to end on February 19, barring "unforeseen developments".
It is believed there are 78 people with British passports – including crew – on the Diamond Princess.
There are no plans to fly anyone from the ship and back to the UK at the moment.
In a statement, the company added: "Princess Cruises can confirm the nationalities of the 41 people who were tested positive for coronavirus are from Argentina (one); Australia (five); Canada (five), Japan (21); United Kingdom (one) and United States (eight)."
The latest diagnoses comes as as health experts issued a new warning to travellers arriving from several Asian countries.
The third patient to be diagnosed with coronavirus in the UK is thought to have been diagnosed in Brighton and was transferred to St Thomas’ Hospital in London, where there is an infectious disease unit, on Thursday afternoon.
Two other patients are still being treated at the Royal Victoria Infirmary infectious diseases centre in Newcastle.
One is a student at the University of York while the other is a family member. They had travelled from China in the days before their diagnosis.
The Government is now urging travellers from countries including Thailand, Singapore, Japan and South Korea to self-isolate if they begin to feel unwell.
Other countries on the list are Hong Kong, Taiwan, Japan, Malaysia, South Korea and Macau, as well as mainland China.
Anyone arriving from these locations should stay indoors and avoid contact with other people if they develop symptoms such as a cough, fever or shortness of breath, the advice warns.
Until Thursday, this advice only related to people travelling from Wuhan in China.
The UK Foreign Office has advised Britons in China to leave if they are able to.
More than 80 UK citizens and family members who were the first to be quarantined at Arrowe Park Hospital on the Wirral have been told they can leave next Thursday.
The group are spending 14 days in isolation but will be released next week as long as they remain symptom-free.
A separate ship in Hong Kong, the World Dream, has about 66 British passport-holders on board, officials said.
Nobody on that ship has tested positive and it is understood hat passengers are unable to leave the ship but are not in quarantine and can move around freely on board.
The global death toll from coronavirus rose to 636 on Friday, with the number of confirmed cases rising to 31,161. Some 260 cases have been recorded outside China.
It emerged on Thursday that the Chinese doctor sanctioned by the authorities for issuing an early warning about the coronavirus has died from the illness.
The Wuhan Central Hospital said on its social media account that Dr Li Wenliang, a 34-year-old ophthalmologist, was “unfortunately infected during the fight against the pneumonia epidemic of the new coronavirus infection”.
Mr Li was reprimanded by local police for “spreading rumours” about the illness in late December, according to news reports.
Meanwhile, a newborn baby has become the youngest to be diagnosed with the disease.
Only a handful of children have come down with the new coronavirus, which has been most severe in older people.