Before the 1981 merger, the neighbouring municipalities of Nummi were Kiikala, Lohja, Pusula, Sammatti, Somero (until 1977, Somerniemi), Suomusjärvi and Vihti.

In 1822, a new stone church was built in the neoclassical style by the shore of Lake Pitkäjärvi.

The Finnish Heritage Agency has recorded over a hundred relics found in the Nummi and Pusula area.

The Nummi village centre and church area together are a nationally valuable built environment protected by law.

[5] The hamlets of Nummi are: Haarla, Hakula, Heijala, Heimola, Huhti, Hyrsylä, Hyvelä, Immola, Jakova, Järvenpää, Jättölä, Korkianoja, Kovela, Leppäkorpi, Luttula, Maikkala, Maskila, Mettula, Miemola, Millola, Mommola, Mäntsälä, Nummi, Näkkilä, Oinola, Oittila, Pakkala, Pälölä, Raatti, Remala, Rettlahti, Röhkölä, Salo, Saukkola, Sierla, Sitarla, Tavola, Varttila and Vivola.