The 2020 program features 53 presenting companies, up from 50 last year.
Diggers chairman Jim Walker said the sector was in excellent health and every session featured companies that would attract strong investor interest.
"The line-up also includes 14 companies that have not presented before," he said.
"As usual, the program is a broad representation of companies producing or exploring for gold, nickel, copper, zinc, battery metals, iron ore, bauxite, rare earths, minerals sands, potash and uranium."
As always, gold companies dominate the line-up, accounting for 28, or just over half, of the presenters.
The only two of the 10-strong ASX 200 gold producers not to present will be Silver Lake Resources and Perseus Mining.
Overseas-based gold producers AngloGold Ashanti, Gold Fields and Kirkland Lake Gold will present, though will almost be certainly represented by regional heads due to international travel restrictions.
New faces on the program include MNN Awards Explorer of the Year nominees Chalice Gold Mines, De Grey Mining, Alkane Resources, Apollo Consolidated Legend Mining and Tietto Minerals.
Capricorn Metals, Musgrave Minerals, OreCorp, Mineral Commodities, NTM Gold and Poseidon Nickel will also feature.
While BHP Nickel West returns, Rio Tinto will not present this year after speaking the past two years.
Diggers organisers said the 2020 keynote was still to be confirmed.
Ian Goldin was announced as this year's keynote in February, though the Oxford University professor is unlikely to make it to Australia.
In March, Diggers organisers made the decision to delay this year's event from August until October 12-14.
The forum says 154 exhibitors have been confirmed across two marquees.
Organisers urged attendees to book flights and accommodation due to high demand.
Western Australia premier Mark McGowan is yet to announce a date for the state's border to reopen.
"Despite the challenges everyone has faced this year, we are looking forward to providing the industry the opportunity to again showcase itself at the Diggers & Dealers Mining Forum," Walker said.