Port Talbot actor Michael Sheen was behind the bid to bring the event to Cardiff.
Almost 500 footballers from around the world have arrived in Wales to compete in the Homeless World Cup.
The week-long event begins in Cardiff’s Bute Park at lunchtime.
Created to harness the power of sport in transforming the lives of people experiencing homelessness and social exclusion, over one million people worldwide have had their lives positively impacted by the tournament and its programmes since the first tournament in Graz, Austria in 2003.
Recent hosts of the annual tournament include Mexico City (Mexico), Oslo (Norway), Glasgow (Scotland) and Santiago (Chile).
The Cardiff 2019 Homeless World Cup bid was led by Welsh actor and activist Michael Sheen, who has taken a hands-on role in the organisation of the event.
With homelessness at its worst point in decades in the city, across Wales and the UK, the tournament is working to create a legacy which has a real impact on people’s lives long after the final whistle is blown.
Michael Sheen said: "When I attended the Homeless World Cup in Oslo in 2017, I knew we had to bring it to Wales. Making it happen immediately became an ambition of mine, especially as I knew it was already a dream of many within an incredible organisation called Street Football Wales, that I had started working with in 2016.
"And just two years later that dream is very much a reality, and I for one could not be more proud of what an extremely dedicated group of people have managed to achieve in bringing this wonderful tournament to Wales.
"For those of you who are unfamiliar with the Homeless World Cup, and I am imagining that is many of you, I promise you that it is a sporting spectacle that is quite unlike any other. It is of course a football tournament, but it is one that is far more than simply a game.
"It changes lives for the better. I have seen it happen and it is my fervent hope that this year’s tournament will provide many more opportunities for its transformative effects to be experienced by those who need it most long after the final whistle is blown."
The Welsh teams are selected through Street Football Wales, who have been behind programmes to aid social inclusion through sport since the inaugural tournament back in 2003. Keri Harris has managed the team throughout that time, running four leagues with 40+ teams around Wales for people experiencing homelessness and social exclusion.
Keri Harris, Director & Founder of Street Football Wales, and Squad Manager for both Welsh teams at the Homeless World Cup in Cardiff, said: "I never thought I would see the day that the Homeless World Cup came to Wales. But it’s really happening!
"This is my seventeenth Homeless World Cup and to experience it here in Wales is something else. I’m literally bursting with pride and our players are so excited to play for their country in front of a home crowd. I mean what could be better? Let’s show them how it’s done Wales!"
Mel Young, co-founder of the Homeless World Cup Foundation said: "The Homeless World Cup is truly a life changing event. Since 2003 we have witnessed transformations to the lives of thousands of players and a wonderful spectacle of football.
"The Cardiff 2019 Homeless World Cup will be a fantastic event, the city and its people have embraced our event truly and are welcoming players from all around the world to enjoy this festival of football that will, without a doubt, change the lives of participants and spectators alike."
The opening day of the tournament
The opening match of the tournament kicks off at 12.30pm on Saturday 27th July and follows a huge Cardiff city centre parade featuring the teams, coaches and staff of all participating nations.
The parade begins at the Principality Stadium (Gate 4) at 11.20am before marching through the city centre streets, accompanied by a marching brass band and a samba band. The procession is scheduled to arrive in Bute Park for 11.50am ahead of an opening ceremony attended by Michael Sheen and Mel Young, co-founder of the Homeless World Cup Foundation.
Here players and the public will be entertained by the likes of Only Boys Aloud, before the Welsh national anthem which heralds the beginning of play at 12.30pm, sung by Welsh singer/songwriter, Shellyann Evans, winner of the BBC singing show, All Together Now.
The opening match of the tournament will be Wales men against Denmark men. This will be followed by Wales women versus Northern Ireland women.
Daily updates thereafter will be available on the Homeless World Cup website and social media channels.