A by-election was held in the Tongatapu 9 constituency of Tonga on 15 September 2011. It was triggered by the death of the incumbent, the first time MP Kaveinga Faûanunu, who died of head and neck cancer on 24 July. Under the first past the post system, Faûanunu had won the newly established single-member seat for the Democratic Party of the Friendly Islands in the November 2010 general election, with 34% of the vote, and a majority of 494 votes (18.5%), appearing to make it a relatively safe seat for the party (which was a junior partner in Lord Tuûivakano's government).
On 18 August, the Tongan government announced that six candidates had been registered for the by-election, without however specifying what political party any of them might be a member of. They were Konisitutone Simana Kamii, Siaosi ûEnosi Tuûipulotu, Viliami Fukofuka, Sevenitini Toumoûua, ûEpeli Taufa Kalimani, and Falisi Tupou. The first five had stood unsuccessfully in the November general election â most notably Sevenitini Toumoûua, who had finished second to Faûanunu with 15.5% of the vote.
Falisi Tupou, the candidate of the Democratic Party of the Friendly Islands, won the seat with 32.8% of the vote.