The 38-year-old Welsh winger, one of three over-age players in the 18-man squad, is taking part in his first international tournament and will captain the side for the first time when it plays Brazil in a warm-up at Middlesbrough on July 20.
The appointment was confirmed on the English FA's website (www.thefa.com) on Sunday.
Giggs has won 12 Premier League titles, five FA Cups and two Champions Leagues with Manchester United and is the most decorated player in English soccer history but has never played in a major championship because of Wales' failure to reach either the World Cup or European finals during his long career.
The match against Brazil will be the first time Britain have fielded an Olympic squad since they played Bulgaria in a qualifier in 1971 ahead of the Munich Olympics the following year. They last played in the finals in 1960.
Britain faces Uruguay, United Arab Emirates and Senegal in their group stage matches. - Reuters
