Deputy mayor Jenny Duncan and students from Mosston School lead the march to Majestic Square.
Whanganui people have joined together to show their support for the Muslim community.
Hundreds of people turned out for the Whanganui Unity March from Cooks Gardens to Majestic Square at lunchtime on Friday.
The march along Maria Pl was led by Whanganui deputy mayor Jenny Duncan and children from Mosston School who carried the Whanganui Unity banner.
The crowd heard from community representatives and many stayed for the call to prayer and two minutes' silence at 1.32pm.
New Zealand International Commercial Pilot Academy conducted a missing person flypast in honour of Ozair Kadir, of India, a student at the International Aviation Academy of New Zealand in Christchurch who died in the terror attack.
Islamic Association of Whanganui president Dr Mukarram Mairaj thanked the people of New Zealand and especially the Whanganui community on behalf of the Muslim community.
"New Zealand is my home and this incident will not change my opinion about New Zealand," Mairaj said.
Gerrard Albert spoke on behalf of Whanganui iwi about the need to continue to fight to accept those who are different to us.
"If we say my tikanga is the only one to be accepted we have lost our humanity. They could be any one of us, any one of our family."
Individual responsibility to change attitudes needed to continue beyond today's gathering, Albert said.
Whanganui MP Harete Hipango said the atrocity "breached our nation but has made us united more than ever before".
She acknowledged the work of the first responders in Christchurch and thanked Whanganui police who were at the march.
"There is unity in our humanity," she said.
Hipango reminded the crowd of a verse, not often sung, of the New Zealand national anthem:
"Men of every creed and race, Gather here before Thy face, Asking Thee to bless this place, God defend our free land. From dissension, envy, hate, And corruption guard our state, Make our country good and great, God defend New Zealand."
Vijeshwar Prasad, of the Multicultural Society, said some people tried to blame migrants for "stealing their jobs" or taking housing and they needed to rethink their attitudes.
"Limited knowledge is a very dangerous thing and that's what's happening in this country," Prasad said.
"One person cannot do it alone. We can do it together and improve the situation. We must break barriers and with love we can help one another. You have shown today that you are united and there will be strength.
"Let's all pray that those precious lives we have lost will rest in peace."
Dr Nafees Ghamri told the gathering Muslim communities were overwhelmed by the reaction of people throughout New Zealand and the support and love they had been shown.
He acknowledged the support of the government, political parties, social organisations and media.
However, he said Islamophobia in New Zealand society had not been addressed earlier and had progressed from fear to hatred.
The support many people had shown after the attack may be a reflection of the future of New Zealand and the upcoming generation, Ghamri said.
Mayor Hamish McDouall said the attack had shaken people's sense of self, community and place but we should not let the terrorist "shake our kaupapa".
McDouall urged the crowd not to accept casual racism any longer and said he would be calling out anyone who communicated with him with any sort of racist message.
"If we draw a line from Friday we can make our entire society a better place and something good can grow from such a terrible tragedy," he said.
The crowd joined hands around Majestic Square as MC Carla Donson read out the names and ages of those who died in the attack before the call to prayer and two minutes' silence.
Whanganui Unity March organiser Jack Bullock told the Chronicle he was pleased with the turnout and support.
"Our community has come out and shown we are a kind, loving community," he said.
"Today has brought people together who wouldn't normally stand together."
Commemorations will continue this weekend, with the Marton community invited to a vigil on Saturday, March 23.
"Marton for Christchurch" will be at Marton Rugby Park, Follett St, 1pm-3pm. People are invited to bring a picnic and a plate to share with someone else. Donations will be collected for the Christchurch victims.