Officers were called after reports of a party in the Agbrigg area on Saturday evening.
Police said there were 25 people inside the house who were clearly breaching coronavirus regulations.
Everyone inside was issued with a fixed penalty notice, according to West Yorkshire Police's Wakefield North East and Rural team.
A police spokesman said: "Officers attended an address in the Agbrigg area this evening due to reports of a house party.
"On attending officers noted 25 people inside the property clearly breaching Covid-19 legislation.
"All persons in the property were issued with a fixed penalty notice."
Under the latest lockdown rules, people in England must stay at home and only go out for essential reasons.
The police have a legal duty to make sure the rules are enforced, and you could be issued with a fixed penalty notice if you break the rules.
Since March, some 32,000 have been issued in England and Wales.
Fines start at £200, but large parties can be shut down by the police - with fines of up to £10,000.
Reasons to leave home include:
Work or volunteering where it is "unreasonable" to work from home. This includes work in someone else's home, such as that carried out by social workers, nannies, cleaners and tradespeople
Education, training, childcare, medical appointments and emergencies
Exercise outdoors (limited to once a day). You can meet one other person from another household in an open public space to exercise
Shopping for essentials such as food and medicine
Communal religious worship
Meeting your support or childcare bubble. Children can also move between separated parents
Activities related to moving house