On 25 April 1956, Grainger was selected for a Football League representative match against the Irish League in Belfast, which ended in a 5–2 defeat. He earned his first England cap on 9 May 1956 in a friendly with Brazil at Wembley Stadium. He scored within the opening minutes with his first touch of the ball and in the 83rd-minute headed in England's fourth. Of his debut against Brazil, Grainger said: "When you think of the talent in that England team, with Duncan Edwards, Billy Wright and Stanley Matthews, you delight in what might have been. We will never know how good the team could have been because Munich cheated us. But in 1956, we scored four against Brazil at Wembley and we even missed two penalties. That was how superior we were that day. Two years later, Brazil won the World Cup." He picked up two further caps in a tour of Scandinavia, in a 0–0 draw with Sweden and 5–2 victory in Finland. It was during this tour that his reputation as a singer became established after Nat Lofthouse asked him to sing at a bar attended by football journalists. The tour ended in a trip to Berlin to face West Germany on 26 May, the World Cup champions of 1954, a game England won 3–1 and that won Grainger praise from the British and German press, with England manager Walter Winterbottom effusing that "I was extremely pleased with Colin Grainger".