There are three island names in Shetland of unknown and possibly pre-Celtic origin: Fetlar, Unst and Yell.

The Fetlar Foy, once very popular with Shetlanders and tourists alike, took place at midsummer on the Links at Tresta where folk were entertained with music, food and drink.

[14] Its most famous son was Sir William Watson Cheyne Bt FRS FRCS, a close associate of Lord Lister and one of the pioneers of antiseptics.

Fetlar was home to the Society of Our Lady of the Isles, an Anglican religious order for women, until it moved to Unst in 2015.

The bottle, and Mr Leaper's World Record certificate, have been donated to the Fetlar Interpretative Centre.

[15] Fetlar also has an international selection of shipwrecks including Danish, Dutch, German, English and Soviet vessels.

[4] Fetlar has a very complex geology, including gneiss in the west, metamorphosed gabbro and phyllite, and kaolin.

[4] The east of the island is part of the Shetland ophiolite complex (a section of the Earth's oceanic crust and the underlying upper mantle that has been uplifted and exposed above sea level).

[10] The northern part of Fetlar is a RSPB reserve, home to several important breeding species including Arctic skuas and Eurasian whimbrels.

The Lamb Hoga peninsula and nearby Haaf Gruney have some of the largest colonies of European storm petrel.

[25] Fetlar Developments Ltd (FDL), a company limited by guarantee and a registered charity, was set up by the community to counter the depopulation of the island, which had fallen to just 48 in early 2009, when the 2001 total had been 86.