Rabbi Eli Schlanger, 41, died when two gunmen - a father and son - targeted a Hanukkah celebration at a park next to the beach on the first day of the Jewish festival of lights on Sunday evening.
One of the attackers, a 50-year-old man, was killed along with 15 innocent people, aged between 10 and 87 years old.
The other gunman, who has been named as 24-year-old Naveed Akram, is in a critical condition, police said.
A 10-year-old girl died in hospital following the attack, while Israel's foreign ministry has said one of the country's citizens is also among the dead.
Follow live: 15 people and gunman killed at event celebrating Hanukkah
Mr Schlanger was assistant rabbi at Chabad of Bondi, a Jewish cultural centre.
HIs cousin Rabbi Dovid Lewis, of the South Manchester Synagogue, told Sky News their great-uncle, the late Reverend Leslie Olsberg, served as a rabbi at the Heaton Park Synagogue in the city, where two people were killed in a terror attack on 2 October.
He said his cousin had "dedicated his life to adding light and to spreading Torah and Judaism" and in the wake of the Manchester attack sent a post on social media saying: "We will respond with light."
"There's a feeling of numbness but there's also a feeling he lived," he said.
"I'm not going to wallow in pity, I'm going to do something in his memory."
He said his cousin "lit a light", adding: "I'm now obliged to pick up that light and become a torch bearer."
He added: "We have got to say darkness can only be combatted with light. It's what he did, it's what I will do, it's what we ask everyone else to do as well."
Mr Schlanger was a father of five who, along with his wife Chayala, celebrated the birth of their youngest child, a boy, two months ago, and grew up in Temple Fortune, north London. according to Jewish News.
Another one of his cousins, Brighton-based Rabbi Zalman Lewis, described Mr Schlanger to Sky News as an "incredibly vivacious, energetic, positive guy" who had "dedicated his life to helping people".
Read more:
What we know so far about Bondi Beach shooting
He said his initial reaction was one of "deep pain and confusion" but he quickly knew he had to respond with a "positive message of hope and light and and positivity".
"The world is a good place," he said.
"There is some evil. There is some darkness. But overwhelmingly there is goodness in the world. And overwhelmingly there are good people in the world. And I came home and I said to myself, I need to create a positive energy for myself, for my family, for my community."
Parents messaged their children and teenagers, who had been enjoying a late afternoon swim at Bondi.
Witnesses said police were on the scene quickly, and the streets of Sydney's eastern suburbs were full of police cars and ambulances on their way to Bondi.
Follow live: 11 people killed at event celebrating Hanukkah
When we arrived, there were still dozens of people processing what had happened, and everywhere - shock.
Witnesses told us that when the gunfire started some people took cover in the North Bondi Surf Life Saving Club. Once the threat was over, lifeguards helped the injured and used surfboards to carry them out.
Some people were clearly traumatised and provided graphic detail of witnessing the shooting and seeing people killed in front of them.
A photographer, Danny, was covering the Jewish holiday event.
Read more: What we know so far
He said he "locked eyes" with one of the gunmen, who then fired towards him. Danny said he was grazed by a bullet. He kept filming during the shooting, while taking cover.
Sam, from France, was working at Bondi. He went to the scene of the attack and saw almost a dozen people lying on the ground covered in blood. Sam described it as like a "war zone".
Rabbi Lei Wolff, from Central Synagogue in Sydney, went to Bondi as soon as he heard about the mass shooting. A dear friend of his, Rabbi Eli Schlanger, was killed in the attack.
Rabbi Wolff has called on people around the world to stand with Australia's Jewish community against terrorism.
Here is what we know so far about what happened in the Australian coastal city.
How many people were killed or injured?
Among the 16 fatalities are a 10-year-old girl. Those killed range in age between 10 and 87, according to New South Wales police.
Another 40 people remain in hospital, including three children. Five people are critically ill, with the others either in serious or stable condition.
These police figures include the two suspects, one of whom was killed at the scene, while the other is in custody in a critical condition.
Only one victim has been identified so far. The family of British-born Rabbi Eli Schlanger, an assistant rabbi at Chabad of Bondi, have paid tribute to him.
Israel's foreign ministry also said an Israeli citizen had been killed.
How did the shooting unfold?
More than 1,000 people were at an event celebrating the Jewish festival of Hanukkah at the time of the shooting, police said.
Officers were called at about 6.47pm on Sunday (7.47am UK time), as they responded to reports of shots being fired at Archer Park, Bondi Beach.
New South Wales Premier Chris Minns said two individuals fired on a "crowded group of families" at the park in a "cowardly act of terrifying violence".
Officers have declared the attack a terrorist incident.
One video showed two gunmen appearing to open fire from a small bridge overlooking the beach, while another showed fleeing crowds running on the beach.
In a third video, a bystander can be seen wrestling a rifle from one of the gunmen.
Ahmed al Ahmed, 43, who was shot twice in the incident, then aims the weapon at the attacker, who seems to run towards his accomplice on a bridge.
Who are the suspected gunmen?
One of the suspected gunmen is 24-year-old Naveed Akram, who was critically injured.
His driver's licence says he lives in Bonnyrigg, a suburb of Sydney.
The identity of the other suspected attacker, who died at the scene, is not known but police say he was 50-years-old.
What have witnesses said?
Witnesses have described the terror and confusion as masses of people fled the beach.
Arsen Ostrovsky was injured and said the shooting was an "absolute bloodbath".
He said he had also "survived October 7th" - the Hamas attack on Israel two years ago.
He told Sky News Australia he had only been in Australia for a fortnight.
Mr Ostrovsky said: "I lived in Israel the last 13 years. We came here only two weeks ago to work in the Jewish community, to fight antisemitism, to fight this bloodthirsty, ravaging hatred. That's why I'm here. You know, we've lived through worse. We're going to get through this."
He added: "I saw at least one gunman firing. Looked like a shotgun, firing randomly in all directions. I saw children falling to the floor, elderly, I saw invalids… it was just an absolute bloodbath."
Elodie Obkircher told Sky News she and her boyfriend were at the nearby North Bondi RSL club when the shooting happened.
She said: "We heard 10 gunshots. So everyone dropped down to the ground. A lot of us were crying and shaking. It was very traumatic.
"It was absolute chaos.
"We could hear the rounds of shots. At first, everyone thought it was fireworks, but I saw people running along the beach. I've never seen so many people running.
"We could see everyone hiding behind their cars. And then as soon as we heard the shots, 10 rounds go, we knew it was a gunman."
Another witness told 9News there were "thousands of people just like running".
"And I opened up the back gate to my friend's cafe and just let everyone in. Pregnant women, women with kids, just everyone's running.
"It was pandemonium."
Meanwhile, Rabbi Levi Wolff, of Central Synagogue Sydney, went to the scene when he was informed about the shooting.
He told Sky News: "We are on the eve of the Jewish holiday of Hanukkah, known as the Festival of Lights, and there was about to be a public menorah lighting for the first night of the Jewish holiday.
"And the gunmen were just shooting at those who were there present for the menorah lighting."
Rabbi Wolff went on to say that his colleague and friend, Rabbi Eli Schlanger, was killed in the terror attack.
He said he was "full of light, full of unbelievable energy" and "gave so much of himself to this very community".
Jewish News, speaking to Mr Schlanger's cousin, reports that he was born in London.
What have police said?
Police said their operation was "ongoing" and a "number of suspicious items located in the vicinity" were being examined by specialist officers.
An exclusion zone was in place, they added.
They later said a police bomb disposal unit was working on a suspected improvised explosive device in one of the suspects' cars.
Police also raided the home of a suspect in the suburb of Bonnyrigg.
How have world leaders reacted?
New South Wales Premier Chris Minns called it a "horrifying evil attack" while the country's prime minister Anthony Albanese said it was a "devastating" terrorist attack that struck at the heart of the nation.
Donald Trump said it was "terrible" and "antisemitic", but also praised the "very brave" man who tackled one of the gunman.
King Charles said he and Queen Camilla were "appalled and saddened" while Sir Keir Starmer described the shooting as "sickening".
Israeli PM Benjamin Netanyahu said it was "cold-blooded murder", but also pointed out that he had previously warned Anthony Albanese about growing antisemitism in Australia.
The man, named by a relative as 43-year-old Ahmed al Ahmed, was seen in a video running up to the attacker from behind and then grabbing the shotgun from his hands before pointing the weapon back at him.
The footage then showed the terrorist heading towards a bridge where another gunman was located, while the bystander placed the gun beside a tree.
Live updates on Sydney shooting
Mr Ahmed, who was wearing a white T-shirt, was shot twice in the incident and was due to have surgery, his cousin, Mustafa, has revealed.
In a video on 7News, Mr Ahmed appeared to have a bloodied arm and hand, and was helped by other people near the scene in the Australian city.
At least 16 people were killed, including one of the gunmen, and 40 others were injured in the attack.
Two gunmen opened fire from a bridge on crowds at a Jewish event around 6pm local time on Sunday evening.
More than 1,000 people had been at the gathering which was celebrating the festival of Hanukkah.
A gunman was killed and another was in a critical condition following the shooting.
One of the suspects was 24-year-old Naveed Akram.
His driver's licence says he lives in Bonnyrigg, a suburb of Sydney. The identity of the other suspected attacker is not known.
Mustafa said father-of-two Mr Ahmed, who owns a fruit shop in the Sydney suburb of Sutherland, did not have any experience with guns but was just walking past when he decided to step in.
He told 7News: "He's in hospital and we don't know exactly what's going on inside.
"We do hope he will be fine. He's a hero, 100%."
Read more:
What we know about mass shooting
The footage of the bystander's actions spread quickly on social media as people praised the man for his bravery, saying his actions had potentially saved many lives.
"Australian hero (random civilian) wrestles gun off attacker and disarms him. Some people are brave and then some people are... whatever this is," one person said on X, sharing the video.
"This Australian man saved countless lives by stripping the gun off one of the terrorists at Bondi beach. HERO," another said.
Chris Minns, the premier of New South Wales state, where Sydney is located, said it was the "most unbelievable scene I've ever seen".
"A man walking up to a gunman who had fired on the community and single-handedly disarming him, putting his own life at risk to save the lives of countless other people."
"That man is a genuine hero, and I've got no doubt that there are many, many people alive tonight as a result of his bravery," he added.
The country's prime minister Anthony Albanese praised the actions of Australians who had "run towards danger in order to help others".
"These Australians are heroes and their bravery has saved lives," he told a news conference.
Shabana Mahmood said the dedicated units will be in place across every force by 2029 as part of Labour's violence against women and girls (VAWG) strategy due to be launched later this week.
The use of Domestic Abuse Protection Orders (DAPOs), which had been trialled in several areas, will also be rolled out across England and Wales. They are designed to target abusers by imposing curfews, electronic tags and exclusion zones.
The orders cover all forms of domestic abuse, including economic abuse, coercive and controlling behaviour, stalking and 'honour'-based abuse. Breaching the terms can carry a prison term of up to five years.
Nearly £2m will also be spent funding a network of officers to target offenders operating within the online space.
Teams will use covert and intelligence techniques to tackle violence against women and girls via apps and websites.
A similar undercover network funded by the Home Office to examine child sexual abuse has arrested over 1,700 perpetrators.
Abuse is 'national emergency'
Challenged on Sunday Morning with Trevor Phillips on the amount of funding and whether it could be effective, Ms Mahmood said it would be a "pilot scheme for 18 months" because "we've never gone into the online space looking at violence against women and girls".
"We'll be setting out more of our proposals on those specifics later in the coming week," she said.
"But I think it is important that the state take some action because, you know, we're not willing to sit back and just accept that violence against women and girls is a fact of life.
"And I think for too long across society, it's just something that we expect is just something that's normal. And we're calling time on that."
The target to halve violence against women and girls in a decade is a Labour manifesto pledge.
The government said the measures build on existing policy, including facial recognition technology to identify offenders, improving protections for stalking victims, making strangulation a criminal offence and establishing domestic abuse specialists in 999 control rooms.
Read more from Sky News:
Demands for violence and abuse reforms
Women still feel unsafe on streets
Minister 'clarifies' violence strategy
Ms Mahmood went on to say there was a "postcode lottery" for victims and survivors in terms of what response they receive if they lodge an allegation.
"We want to turn that around," she said. "That's why we think it has to be a national programme of making sure that these teams are rolled out across the country."
Labour has 'failed women'
But the Conservatives said Labour had "failed women" and "broken its promises" by delaying the publication of the violence against women and girls strategy.
Shadow home secretary Chris Philp said that Labour "shrinks from uncomfortable truths, voting against tougher sentences and presiding over falling sex-offender convictions. At every turn, Labour has failed women".