RSPCA Cymru said it had responded to 92 incidents, with 57 seals being collected and taken to centres for rehabilitation.
The group released photos of two seal pups which were found stranded and underweight on beaches in Pembrokeshire and the Vale of Glamorgan.
The pups will be released into the wild once they recover.
Most female seals give birth in autumn in Wales, meaning more pups are living off beaches during winter months, which can lead to an increased number of rescues.
One of those rescued was found on 22 December by RSPCA officers near Aberthaw, Vale of Glamorgan, with a cut to its chin, as well as suffering from exhaustion and weight loss.
A second underweight pup was rescued on Boxing Day at Monkstone Point, near Saundersfoot, Pembrokeshire.
Officer Ellie West, who found the seal at Monkstone Point, said: “This seal pup was underweight, but luckily didn’t have any injuries.
“Looking back at this seal season, we have had around 92 incidents in the south-west Wales area, and 57 of these seals have been collected by us.”
The seals have been sent to rehabilitation centres in Taunton, Somerset and Nantwich, Cheshire, and will be released back into the wild once they recover.