Show bosses have told the former X Factor star that they want her on the panel alongside David Walliams and veteran judge Amanda Holden.
Michael McIntyre quit the show earlier this year, while Baywatch legend David Hasselhoff has been axed, the Sunday Mirror reports.
"Everybody is really excited about the new lineup," a source said. "David was confirmed this week and the producers think it's the best yet. He's a real favourite with the nation and Dannii is hugely popular. It's exciting for her to be coming back."
Minogue has requested to have her filming schedule confirmed within days to avoid a repeat of the problems which led to her X Factor departure earlier this year. Britain's Got Talent will need to fit around her son Ethan, or Minogue will instead return to Australia's Got Talent.
"She needs confirmed shooting schedules and dates for the entire series before she packs her bags and lets other opportunities go," the source added. "It starts shooting in just a few weeks and she does have other offers to think about and consider.
"She doesn't want what happened last time to happen again. Being a mum she has to plan ahead. It's as simple as that - Ethan is the priority. Dannii was really disappointed not to be able to return to the UK for this year's X Factor, so she wants to make this work."
Minogue, who will sign her contract within the next couple of weeks, previously insisted that she had no immediate plans to return to British TV.
Confirming her return, Holden wrote on Twitter: "You will all have to be patient re BGT. I am doing it inc auditions! But the rest will be an official announcement soooon! (sic)"
A Britain's Got Talent spokeswoman said the reports were "all speculation at the moment".
> Dannii Minogue "excited" about musical comeback