It’s time to shell-ebrate!

A tortoise named Tommy has become the world’s oldest living pet after celebrating her 121st birthday this week — and boy, has she seen a thing or two.

The endangered Hermann’s tortoise has been in the same British family since she was purchased for £1 in 1909, living through 21 US presidents, six different English monarchs and two world wars.

“She’s been through the family all these years and we all love her to bits,” owner Sheila Floris told the UK Metro on Monday.

Tommy was born in 1898 and was purchased by Sheila’s grandmother Margaret Cloonan when she was already 11 years old.

At that time, William McKinley was the US president and Queen Victoria was the monarch of the United Kingdom of Great Britain and Ireland.

New York City as we know it today didn’t exist, either. The five boroughs were separate counties before they were consolidated by mayor Robert Van Wyck that year.

Floris, 62, has been caring for Tommy since she was 5 years old and said the beloved pet was mistaken for a boy until she began laying eggs.

“It was too late to change the name so the name has stuck ever since,” she said.

“She was lovely to grow up with. I remember her racing around the garden and being quite speedy.”

The Surrey woman says Tommy hibernates six months of each year and has never been taken to the vet — crediting her excellent bill of health to plenty of love and a healthy diet of garden weeds.

“Tommy still makes us laugh by racing around the garden, if I go outside I’ll call her name and she’ll come out to me,” Floris said.

Most Hermann’s tortoises typically live to be 50 and are native to Turkey, eastern Italy and Greece.

They were listed as an endangered species in 2012 and are known for having individual personalities and developing a bond with their owners, according to Petguide.com.

Tommy is also about to outlive the world’s oldest person, Jean Calment, who lived to be 122 until her death in 1997.

“She’s like a family member,” Floris said. “She’s like a duchess, we’ve all grown up with her.”