Around 300 people attended the illegal gathering in an 'igloo style' tent with a sound system in Deighton, Huddersfield, on Saturday night.
Two men, aged 29 and 42, have been arrested today on suspicion of breaching Covid-19 legislation regarding public gatherings.
They remain in custody.
A spokesman for West Yorkshire Police said: "Kirklees CID are continuing to investigate the incident on the evening of Saturday, August 22 in which a group of several hundred persons gathered at an igloo style tent with a sound system in Deighton.
"Officers have today arrested two Huddersfield men aged 29 and 42 on suspicion of public order offences in relation to a breach of Covid 19 legislation regarding public gatherings. They remain in custody for questioning.
"Officers deployed to the unlicensed event on Saturday night and dispersed large crowds present.
"Music was quickly turned off on police arrival and attending officers also removed sound equipment from the location."
Fines of up to £10,000 for those organising illegal raves in England will come into force on Friday as authorities also clamp down on unlawful gatherings.
Police across the country have seen a surge in unlicensed music events in recent weeks, including in Yorkshire where 200 people flocked to an illegal rave at Kirkstall Nature Reserve in Leeds.