A US man has been given probation and fined $US300 for tattooing "DB" on a toddler while drunk.

A social worker from the Georgia Department of Family and Child Services (DFCS) saw the tattoo on the child's shoulder, and police arrested 26-year-old Eugene Ashley shortly after.

The boy was three when the social worker noticed the mark, Floyd County District Attorney Leigh Patterson said.

The man had told police he was drunk and didn't remember tattooing the boy with the letters, the Daily Mail reported.

The letters DB stood for "Daddy's Boy," officials told The Rome News-Tribune.

The child told DFCS the tattoo hurt, Ms Patterson said.

But she admitted the case would have been impossible to go to a jury because the child was too young to testify.

"I don't know if we would be able to elicit a testimony from a child," Ms Patterson said.

Ashley pleaded guilty to tattooing a child under the age of 18 and was given the probation sentence, officials said.