The world's first animal welfare charity, it has branches covering the length and breadth of the country, including here in Sheffield, supported by a dedicated band of fundraisers.
Here, we take a look in our archive at some pictures from the past.
5. Sick swan
"Chippy" the swan which was found with a fractured wing and had been kept at the Spring Street RSPCA centre in Sheffield, left for a new home.
Senior Inspectors Mr Ted Woods (right) and Mr Edwin Ruck put Chippy in the van ready for the journey, February 20, 1959 Photo: Sheffield Newspapers
6. Centenary cake
Celebrating 100 years of the RSPCA Spring Street in 1999 are Tammy Wilson, Audrey Loxley and Yzanne Briggs Photo: Barry Richardson
7. Microchips
Microchipping cats and dogs for their owners are Jo Scott of the Small Animals Unit and animal care manager Alison Pring with Oliver at the South Yorkshire Animal Centre RSPCA Doncaster in May 2000 Photo: Paul David Drabble
8. Open doors
Pantomime Dame Brian Platts officially opens Sheffield RSPCA Open Day at Spring Street in 1996 Photo: Sheffield Newspapers