She was 19-year-old Kaelah Marlow, from Hamilton.
It is understood she was dragged from the water alive after the attack and paramedics administered CPR on the beach to no avail.
Her post-mortem was due to be carried out today.
"Police extend our deepest sympathies to Kaelah's family and loved ones at this very difficult time," police said in a statement.
An eye-witness earlier spoke of the desperate bid to save Ms Marlow's life.
Emergency services rushed to Bowentown Beach just after 5pm yesterday.
Matt Lawry from Kaipaki, holidaying at the Bowentown Beach Holiday Park with his family, said after hearing the sirens he went down to the beach to investigate and so did many other campers.
Lawry said he saw the emergency services first responders working on Ms Marlow for at least 15 minutes and initially thought it was some sort of drowning situation. He said when he learned there had been a shark attack he was stunned.
"The irony is that over the past six or seven days there have been untold shark sightings close to shore, but I never imagined one would try to bite anyone," he said.
Lawry said while the emergency services personnel were working on the young woman there was a man of a similar age sitting on a log nearby with his face turned away being comforted by an emergency services member.
"Watching them try to save the young woman without success and seeing the man's white face was a very traumatic, harrowing experience, " he said.
Lawry said after CPR efforts stopped, a man walked about 50 to 70 metres into the sea, and began splashing water over himself.
Meanwhile, a police officer and one of the first responders stood on the water's edge watching him, he said.
"It was harrowing and I can't stop thinking about the extreme grief I saw on his face as he left the beach."
A stream of people have this morning been laying flowers at the scene and paying their respects.
Eastern Waikato Area Commander, Inspector Dean Anderson said in a statement earlier today: "Police would like to acknowledge the young woman who died yesterday evening at Waihi Beach, and her family and friends at this very difficult time.
He said police were not able to confirm the cause of her death but indications are that she had been injured by a shark.
"A post-mortem is scheduled to be carried out today and this will provide us with a clearer understanding of what happened.
"However, the Coroner will ultimately determine the cause of her death.
Whiting said they were staying at their holiday beach in Seaforth Rd.
"It's so sad and tragic. My heart goes out to the young lady's family. I still can't believe it. We had a bach for 32 years and what has happened is so close to home. It's just terribly sad."
Beach open
The beach will not be closed today.
Surf Life Saving New Zealand confirmed local council officials had made the decision.
But Otawhiwhi Marae have instated a rāhui spanning the North End of Waihi Beach down to Bowentown Heads and in harbour to Ongare, Tuapiro & Tanner Point. The rāhui prohibits the collection of shellfish and all fishing and will remain in place for a week from today (ending Jan 15 at 7am).
Maori warden and Otawhiwhi Marae Trust spokesperson Shaan Kingi said the rāhui was put in place this morning which was customary practice when there had been a water tragedy.
He said it this case it was deemed appropriate to keep the rāhui in place for seven days because there had been a lot of blood on the beach and in the water.
Kingi was the area where the young woman was attacked and died was "very tapu" and extra time was needed to allow the blood to be cleared.
He said he hoped people would respect the rahui which was in place out of respect for the young woman's family and friends who gathered near the Waihi Beach Coastguard headquarters last night.
