Charlie died earlier this month after a battle with lymphoma.
Struggling with grief, Charlie's owner decided to try to put it into words, and penned the obituary, which she titled "Remembering Charlie".
She wrote about everything her dog loved, including snoozing, car rides, bananas and socks.
"He was good at a lot of things, but he was best at unconditional love," she wrote.
"He taught everyone he met about loving people, and always seeing the good in everyone."
Gregory-Hammett also described Charlie's last days, which he spent digging holes at the beach - another one of his favourite things.
"He relaxed in the Charlie-sized holes he dug himself, and dove straight into the oncoming waves. His last days were so happy and will be cherished forever. We will think of him every time we open the peanut butter," she wrote.
"In [lieu] of flowers, the family asks that you give all your pups some extra love in honour of Charlie."
She didn't have the obituary published in the newspaper but created a mock-newspaper so she could have it as a keepsake, and then shared it online.
"I wrote my dog an obituary because of course I did. He was the best boy," she tweeted, alongside a photo of her mock-newspaper obituary.
The tweet has since gone viral, with more than 104,000 likes and thousands of people reaching out to send her their condolences.