Ms Lucas, the leader of the Green party of England and Wales and a current MEP serving the South-East, said voters had made history by electing her to Parliament on a swing of 8.4%, amounting a majority of 1,252 ahead of Labour's Nancy Platts in second place.
"Thank you so much for putting the politics of hope above the politics of fear," she said in her acceptance speech. "I pledge that I will do my very best to do you proud. For once the word historic fits the bill."
The Green Party have been going from strength to strength in recent years and in this past election put up candidates in more constituencies in England and Wales than ever before, fielding more than 300 candidates.
But it was only one that managed to succeed, and Ms Lucas becomes the first Green MP in parliament as I had in fact earlier predicted. Although now only one voice among 650, she is unlikely to make as much impact in the House as her party’s breakthrough is historic.
In the European Parliament, Ms Lucas has always proposed an optimistic and inspiring vision of how dealing with the potential crisis caused by global warming, and although she is the party’s only MP, the Scottish branch of the party has two MSPs in the Parliament at Holyrood.
One of those MSPs, Patrick Harvie, told the BBC that the whole party will be “over the moon to see Caroline Lucas's triumph in Brighton".
"Westminster was always going to be the toughest nut to crack, and Caroline has made an extraordinary breakthrough,” he said.