Some have died and others are seriously ill, with the RSPCA saying the birds were probably feeding on waste products from a local brewery or alcohol producer.
"The birds appear disoriented and confused and struggle to stand," said RSPCA vet David Couper.
"We took some video of one of the birds who is staggering around and losing his balance just like a person would if they'd had too much to drink."
Mr Couper, who has treated the birds at an RSPCA centre in Taunton in Somerset, added: "Sadly, a few of the birds have died but most of them have made good recoveries and have been released after a few days in our care."
He said the birds had been brought in in recent weeks after being found on beaches across Devon, and a few from Bridport and Lyme Regis in Dorset.
One rescue centre has taken in nearly 30 intoxicated seagulls in a fortnight.
"We think they're gaining access to some brewing waste products somewhere," RSPCA officer Jo Daniel said.
"At first, the birds look like they have botulism (an illness caused by bacteria) but then, after vomiting, most seem to recover.
"The birds absolutely stink of alcohol when we collect them so now our vans smell like pubs!"
The animal welfare charity has had more than a dozen similar reports from the south coast.
It is now urging local breweries, distilleries and alcohol producers to check that their waste is secure and cannot be accessed by wildlife or birds.
"These birds were clearly wearing their beer gog-gulls when they scavenged their meal for the day and they've really been suffering with hangovers after a gulls' night out," animal collection officer Clara Scully said.