With Farrell serving a four-match suspension, Lawes will have the honour of skippering the team at Twickenham when he becomes the fifth England player to amass a century of Test appearances.
Lawes made his debut as a 20-year-old against Australia in 2009 and has played some of his best rugby in the twilight years of his Test career.
"We couldn't be prouder of Courtney on achieving his incredible milestone after 14 years of excellent performances for his country," England boss Steve Borthwick said.
"It has been a privilege to watch his journey and witness him develop into a truly outstanding rugby player.
"Not only is Courtney an exceptional talent and an excellent professional, he is also a brilliant role model for young players every time he steps onto the field."
Borthwick has made nine changes to the side thumped 29-10 by Ireland in Dublin, including a first start for hooker Theo Dan in England's last World Cup warm-up fixture.
George Ford is at fly-half in place of regular skipper Farrell, who will miss the first two games of the World Cup while he serves a suspension for his dangerous tackle on Wales' Taine Basham earlier in August.
Giving a hint of his plans for the number eight role following Billy Vunipola's three-game suspension for a high hit, Borthwick picked Ben Earl in the position.
Jonny May has been selected on the left wing despite not being part of England's World Cup squad.
Ollie Chessum follows his replacement cameo against Ireland with a start for the visit of Fiji to step up his return from a serious ankle injury.
Tom Curry misses out once again to continue his recovery from the ankle injury that could threaten his involvement in the World Cup opener against Argentina in France on September 9th.
"Fiji have proven themselves to be a strong opposition and we look forward to what we expect to be an exciting and challenging game," Borthwick said.
"Rest assured that we will be looking to convert the opportunities we have recently been creating week-on-week into points on the scoreboard.
"At this our last Test before heading to France, I want to thank our fans for all the support you continue to give us, and it means a lot to us that you will be behind us all the way on our World Cup journey."
England team to face Fiji (15-1)
Freddie Steward, Max Malins, Ollie Lawrence, Manu Tuilagi, Jonny May, George Ford, Alex Mitchell, Ben Earl, Jack Willis, Courtney Lawes (capt), Ollie Chessum, Maro Itoje, Dan Cole, Theo Dan, Ellis Genge
Replacements:
Jack Walker, Joe Marler, Will Stuart, David Ribbans, Lewis Ludlam, Danny Care, Marcus Smith, Joe Marchant
