Crouch headed in a cross by David Beckham in the 83rd minute to give England the goal it struggled to get all game, and Gerrard added another in injury time to give England its second straight win.
England controlled the play for most of the game, but Crouch and others missed countless good chances in front of the net, raising Trinidad's hopes of holding its second straight favorite to a 0-0 draw.
England striker Wayne Rooney also played, coming on as a substitute in the 58th minute. He replaced Michael Owen.
Beckham took his time and found the Crouch in front of the Trinidad net late in the second half. Crouch leapt over Brett Sancho and headed the ball past Shaka Hislop for England's first second-half goal in a World Cup since 1998.
"It would be fair to say that you haven't seen the best of us yet, but we put ourselves in a good position. We know we can play better," Beckham said.
The English had gone eight games without a second-half goal since Owen scored against Romania in 1998.
"It was so much work. England got so much position on the ball," said Trinidad striker Dwight Yorke, who used to play for Manchester United. "It was a special moment because I have so many friends, so many memories of playing in England."
Crouch's goal brought relief to the face of England coach Sven-Goran Eriksson and his players, who were minutes away from being held to a draw.
"People expected us to walk through this game," Beckham said. "We knew they were going to play 11 men behind the ball. They made it hard for us all game. We knew if we kept to our game plan that we'd break them down."
Trinidad, which held Sweden to a 0-0 draw, nearly got the first goal late in the first half, but defender John Terry made an acrobatic save at the goal line. Stern John headed a ball in the middle of the box that appeared on its way into the net in the 45th minute, only to see Terry making clear it off the goal line while falling down.
That was the best chance for Trinidad, which was outshot 23-7. Any chance at a draw ended when Gerrard beat Hislop with a hard, left-footed shot from the edge of the penalty box in the final minutes.
Gerrard had scored two goals and a penalty kick against Hislop in the FA Cup final, which Liverpool won in a shootout over West Ham on May 13.
Trinidad has one point after two games and will still have a chance to advance to the second round if it can beat Paraguay next Tuesday.
Trinidad's defensive strategy frustrated the English and quieted the crowd that had been singing and cheering loudly at the start of the game.
It was Rooney's entrance that turned the tide. The 20-year-old forward broke a bone in his right foot on April 29 playing for Manchester United and wasn't expected back this soon.
But he was cleared to play by doctors earlier in the day and combined with Lennon, playing his first international game, to bring more energy to an English team that missed many easy chances early on. The struggles prompted the fans to chant Rooney's name in the first half and they broke into a loud standing ovation when he came on in place of Owen.
Owen missed one of England's first-half opportunities when he shot wide all alone in the middle of the box off a rebound in the sixth minute.
Crouch also blew some early chances including one rushed chance all alone in the middle of the box that went well wide.
England: Paul Robinson, Jamie Carragher (Aaron Lennon, 58th), Rio Ferdinand, John Terry, Ashley Cole, David Beckham, Steven Gerrard, Frank Lampard, Joe Cole (Stewart Downing, 75th), Michael Owen (Wayne Rooney, 58th), Peter Crouch.
Trinidad and Tobago: Shaka Hislop, Brent Sancho, Dennis Lawrence, Chris Birchall, Cyd Gray, Aurtis Whitley, Carlos Edwards, Stern John, Kenwyne Jones (Cornell Glen, 70th), Densill Theobald (Evans Wise, 85th), Dwight Yorke.