For the nearly 18,000 Australian residents making citizenship pledges on Australia Day, those were the words the Prime Minister Tony Abbott had reserved for them.

Conducting his first citizenship ceremony before a crowd of hundreds in Canberra, Mr Abbott heard the pledges of 24 of Australia's newest citizens.

"To the men and women taking the citizenship pledge here today, and to the almost 18,000 taking the pledge around Australia, I say welcome to the team."

In Canberra, people from 12 countries, including Argentina, Canada, Denmark and Kenya, were welcomed with cheers, applause and - for one new citizen with a dual cele- bration - a round of happy birthday.

National Australia Day Council chairman Adam Gilchrist said: "I know for all of you it will be a day you never forget."

"I look forward with the new citizens in sharing the qualities that you will bring to our nation to enrich our society: your talent, your skills, and … your commitment.

"Becoming an Australian citizen is a bit like, I guess, joining a family,'' Gilchrist said.

"Like any family, we may not always get along. But in the end we must continue to support each other."

Jenny Nutter, 27, from Fife in Scotland, said it was "a Canberra boy" who brought her to Australia five years ago.

"We met on exchange in the Netherlands," she said.

"I went back to Scotland and he came back to Australia but we couldn't bear to be apart."

The couple will marry in May.

"I didn't expect it to be so emotional," Ms Nutter said of becoming an Australian citizen.

"One of the most wonderful things was walking through the crowd at the end and everyone saying congratulations."

Becoming an Australian citizen on the same day that he and the Citizenship Act turned 65 was destiny for Niels-Jorgen Toxvaerd.

The Sydney man was awarded his citizenship certificate by Mr Abbott and cut a birthday cake with Governor-General Quentin Bryce at the Canberra ceremony.

He has lived in Australia for 20 years and says that over the past few years he realised he felt more Australian than Danish.

''When you are a first-generation immigrant you're always a little bit lightfooted, where to actually belong,'' he said.

''It was a very emotional thing for me just to take the last step and become a citizen, being able to vote and being able to fully participate in Australian society.

''I've realised that's really where I belong now.''

Sunday marked the 65th anniversary of the Nationality and Citizenship Act (renamed in 2007), which created the status of Australian citizen.

Since 1949 more than 4.5 million people have become n citizens.

with AAP