Guests had travelled to the pre-planned party in the Blakenhall area of Wolverhampton on Saturday from as far afield as London.
The party included hired marquees, DJ decks and live musicians.
The flouting of the laws around large gatherings and mixing of households comes as Wolverhampton's Covid alert level remains at 'high' or Tier 2 – with infection rates rising.
WATCH: Police encounter christening party with up to 50 people in Wolverhampton resulting in £10,000 fine
The organiser of the party suggested there were 20 guests, however police officers on the scene saw many more people – and it’s believed more than 40 were present. They were promptly moved on from the illegal gathering in Blakenhall on Saturday.
The household was served with notice of the £10,000 super fine – a first for a residential property in the West Midlands region.
Superintendent Simon Inglis, from Wolverhampton, said: "This was a reckless breach of Covid rules at a time when the deadly virus is spreading and harming our communities.
"It was clearly pre-planned and bringing together this many people at a residential property is not only illegal, but increases the risk of any infections being passed on.
"We are fully aware this is a really difficult time for people, but we won’t be able to control this disease and return to a sense of normality if we allow such events.
"This is not about stopping people’s fun and celebrations, but it is about saving lives from this awful virus.
"The vast majority are following the guidelines and having to make personal sacrifices.
"There are people unable to attend funerals and say goodbye to loved ones while abiding by the restrictions.
"So we must make a stand when we do come across blatant, and unnecessary, breaches such as pre-planned large parties. It is unacceptable and we will take action.
"We are continuing to work with our partners across the city to tackle this virus and help to protect those who live work and visit the city in the coming weeks and months."
Councillor Jasbir Jaspal, Wolverhampton Council’s cabinet member for public health and wellbeing, added: “Every single one of us has a key role to play in the fight against Covid-19, and the vast majority of Wulfrunians are doing a brilliant job in following the measures which are in place to prevent the spread of coronavirus.
“The sacrifices they are making day in, day out, are helping to keep infection rates as low as possible, and I am sure they will be as disgusted as I am at the actions of others who, through their thoughtlessness, are putting people’s lives at risk."