Chichester studied from 1965 to 1968 Geography at the University of Oxford. Since 1969 he worked published in a company that maps and guidebooks from his father, Sir Francis Chichester, founded and named after him. Since 1983, Giles Chichester was Managing Director since 1989 Chairman of the company. In addition, he held senior positions in several other companies, especially in the publishing industry. Chichester is a member of the Royal Geographical Society.
1984-1987 Chichester was chairman of the Conservative Association Hammersmith, from 1988 to 1990 and 1997 to 1998 he was a board member of the National Union of the British Conservative Party, he was also chairman of the political committee of the Carlton Club. In the European elections in 1994, he was first elected to the European Parliament, where he was first a member of the EPP- ED Group. From 2004 to 2007 he was chairman of the Committee on Industry, Research and Energy in the European Parliament, he is also President of the European Energy Forum since 2004.
Until June 5, 2008 Chichester was also head of the British Conservative delegation in the European Parliament. However, he was forced to resign from the post after it was revealed that he had passed on since 1996 proceeds of the secretarial allowance for MEPs to his own company. Chichester argued that the funds were directed at his political staff and were charged only to simplify its administration through private companies. The European Parliament has approved this practice in 1999 and 2004. The Parliament's administration saw it, however, a breach of the financial regulation adopted in 2003 by the Parliament. After a thorough investigation, however, the Secretary General of the European Parliament, Klaus Welle, the allegations went back again because the funds were in fact, not only used for political purposes, for personal gain.
In the European elections in the United Kingdom 2009 Chichester was re-elected again. Like the rest of the British Conservative Party, he joined then emerges from the EPP- ED Group, to join the newly formed European Conservatives and Reformists (ECR). Chichester is a member of the Committee on Industry, Research and Energy. On 5 July 2011, he was voted one of the 14 Vice-Presidents of Parliament after Silvana Koch -Mehrin resigned from this office.