Undefeated American boxer Floyd Mayweather Jr has been denied entry to Australia due to his criminal past.

The 37-year-old, who is due to host two dinner events Down Under, was jailed back in 2012 for attacking his ex-girlfriend two years previously.

"A visa has not been granted in this case," the Daily Mail quotes assistant minister for immigration Senator Michaelia Cash as saying.

"I am aware of Mr Mayweather's background - both in terms of his professional success as well as his criminal history, as has been extensively reported in the United States and Australian media.

"In making character decisions, a range of factors are taken into account. This can include consideration of both a person's criminal history as well as their general conduct over a continuum of time, to reach an assessment as to whether they are of good character."

An online petition was launched to stop Mayweather from visiting Australia due to his previous jail term.