Michael Leeson, 35, was arrested in March 2018 after staff at the child's education establishment noticed severe bruising to the youngster.
An investigation was launched by South Yorkshire Police which revealed the young child had been beaten more than once over a number of weeks.
The child was taken to hospital and a paediatric consultant described the injuries as being "inflicted with as much force as one can imagine".
Leeson, of no fixed abode but formerly from the Doncaster area pleaded guilty to child neglect and was jailed for two years and four months when he appeared at Sheffield Crown Court.
Police have today praised those involved in bringing Leeson to justice.
Detective Inspector Simon Leake,of South Yorkshire Police, said: “This was a heart-breaking case in which the young child was not able to articulate what happened to them, so we did all we could to ensure their voice was still heard.
“I would like to commend the hard work of our partners in health, social care and education, who worked tirelessly to assist our investigation.
“Protecting the most vulnerable in our society remains a force priority, and we will continue to do everything we can to bring those responsible to justice.”
Anyone who suspects a child is in danger is urged to report it to police on 101, or call 999 in an emergency.
Alternatively, you can stay completely anonymous and call Crimestoppers on 0800 555 111
For help and advice about child safety, you can also call the NSPCC on 0808 800 5000.