The Three Lions have carried out the anti-racism gesture before their matches since the death of George Floyd in 2020.
They have decided to continue with the gesture during the tournament in Qatar after recent talks.
"It's what we stand for as a team and have done for a long period of time," said Southgate.
"We feel this is the biggest and we think it's a strong statement that will go around the world for young people, in particular, to see that inclusivity is very important."
Premier League players also took the knee before matches following football's return from the Covid-19 shutdown in the summer of 2020.
It was then decided ahead of the start of this season to use specific moments throughout the season to take the knee rather than making the gesture at every match.
Meanwhile, the Football Association is trying to get clarification over whether captains will be booked if they wear the OneLove Armband in matches in the World Cup.
The captains of nine countries, including England and Wales, had planned to wear the OneLove armband to promote diversity and inclusion.
But Fifa announced new armbands in partnership with three United Nations agencies on the eve of the tournament.
The FA wrote to Fifa in September about the armband but didn't get a response. Their position was that they were willing to take a fine.
They are hoping that they get an answer later on Sunday before the match against Iran on Monday.