British industrialist Sanjeev Gupta will donate the steel to build a new jetty in Whyalla in South Australia's mid-north.
Mr Gupta's commitment comes about a year after his company GFG Alliance took charge of the Whyalla steelworks and follows a $1 million commitment from the state government.
He joined Premier Steven Marshall and Mayor Lyn Breuer in Whyalla on Wednesday to also unveil final design plans for the jetty which is expected to become a major tourism drawcard.
Ms Breuer said the generous donation marked another milestone day for the city as it "continued to blaze a trail of economic growth".
Mr Gupta said he jumped at the chance for GFG Alliance to be a significant contributor to the new jetty.
"Since our purchase of the Whyalla operations almost a year ago, we have stated that we want to play a key role in the growth and development of this community," he said.
"We aim to not only transform our operations, but also partner in further enhancing the city's appeal through developing real estate, tourism and hospitality, recreational facilities and improved transport and access.
"I want Whyalla to be a destination of choice - occupationally and recreationally - for people from across the globe."
The Whyalla council will now call for tenders for the 165-metre jetty and will continue to work with the state government on final planning approval over the next three to six months.
It will also work with the traditional owners in Whyalla, the Barngarla people, to ensure all native title considerations are respected.
