Bobi is a purebred Rafeiro do Alentejo - a breed that has an average life expectancy of 12 to 14 years.
BBC reports the news comes just two weeks after Spike the Chihuahua, 23, was given the record for the oldest living dog.
The previous oldest dog ever was Australia's Bluey, who died in 1939 at the age of 29 years and five months.
As of 1 February, Bobi was 30 years and 226 days old.
This has been validated by the Portuguese government's pet database, which is managed by the National Union of Veterinarians, according to Guinness World Records.
