Youngs reaches milestone
The Leicester Tigers scrumhalf was first capped in 2010.
He starts the opening game of the tournament in an unchanged team from the one that beat Ireland in their last warm-up match.
There is one change on the replacements' bench where Rob Webber replaces Jamie George.
England coach Stuart Lancaster said: "The squad is massively excited to start the World Cup.
"Everyone has worked incredibly hard over the last three months and we are ready.
England managed to become the first northern hemisphere team to win the Webb Ellis trophy whe they beat Australia in the 2003 Final.
Lancaster will be looking to take the cup on English soil.
"All the players have put their hand up in training, and the internationals we have played this summer," said the coach.
"We are blessed to have such a strong squad to select from against a skilful and powerful Fijian side.
"Friday will be a great occasion for the whole squad and for the country.
"We are in a unique position to be playing in a World Cup on home soil and to have the support of a nation behind the team.
"That support will be a massive factor and we don't underestimate its importance.
"I'd like to congratulate Ben Youngs on his achievement.
"To win 50 caps for your country in such a relatively short period of time is testament to Ben's dedication and commitment," added Lancaster.
England: 15 Mike Brown, 14 Anthony Watson, 13 Jonathan Joseph, 12 Brad Barritt, 11 Jonny May, 10 George Ford, 9 Ben Youngs, 8 Ben Morgan, 7 Chris Robshaw (captain), 6 Tom Wood, 5 Courtney Lawes, 4 Geoff Parling, 3 Dan Cole, 2 Tom Youngs, 1 Joe Marler.
Replacements: 16 Rob Webber, 17 Mako Vunipola, 18 Kieran Brookes, 19 Joe Launchbury, 20 Billy Vunipola, 21 Richard Wigglesworth, 22 Owen Farrell, 23 Sam Burgess.
Date: Friday, September 18
Venue: Twickenham, London
Kick-off: 20.00 (19.00 GMT; 07.00 Saturday, September 19 Fiji time)
Referee: Jaco Peyper (South Africa)
Assistant referees: John Lacey (Ireland), Stuart Berry (South Africa)
TMO: Shaun Veldsman (South Africa)
Source: @rugbyworldcup