The tournament in Russia has put the spotlight on the millions of boys and girls living on the streets or working there to support their families.
Sadock John has a very special memory - he scored the first goal in the first Street Child World Cup finals.
Eight years later, he's back at this year's tournament in Russia and full of praise for the organisation behind it.
“Street Child United has made me part of a global community of street kids and former street kids - and has driven me to be the change I want to see in my community,” said Sadock from Tanzania.
The Street Child World Cup puts the spotlight on the issue of millions of boys and girls living on the streets or working there to support their families. More than 200 teenagers aged 14 to 17 from 20 countries have been taking part in this year's event in Moscow.
The United Nations estimates there are up to 150 million street children in the world - but the exact number is unknown because they are often under the radar of education and social services organisations.
Many of them don't go to school, they often have complex circumstances and are very vulnerable to exploitation and violence.
Sadock (pictured below in this Instagram post), who actually scored the first two goals at the South Africa tournament in 2010, has turned his life around in the city of Mwanza.
“I am studying social work at university and am a family outreach support worker, helping young people who are at risk of being on the streets,” he said.
“At the first Street Child World Cup, I realised that I can speak out and I can do whatever I can in order to make the voices of the street children from all over the world be heard.”
A member of this year's Tanzanian team is Steria, a 15-year-old midfielder. He said: "I study but I also like football.
"We are all from the street. We are children living a hard life with no food, no clothes, no anything."
Tanzania's girls' team made it to the final today against Brazil, after beating England 2-1 in the semi-final. The boys' final is between Pakistan and Uzbekistan.
This year's event was co-organised by UK-based charity Street Child United and Russian telecoms company MegaFon, in association with Save the Children. All matches were played at the stadium of Russian champions Lokomotiv Moscow.