Trbovlje (Trifail ) is Slovenia's tenth-largest town, and the seat of the Municipality of Trbovlje. It is located in the valley of a minor left bank tributary of the Sava River in the Central Sava Valley in central-eastern Slovenia.
Trbovlje was attested in written sources in 1220–30 as Trefeul (and as Trevůl and Trevol in 1265–67, Triuella in 1302, Trifeul in 1325, Triueal in 1330, and Triuel in 1424). The name is a feminine plural noun in standard Slovene, but in the local dialect it is declined as a neuter singular adjective. This indicates that the name is derived from *Trěbovľe selo (literally, 'Trěbo's village'), referring to an early inhabitant of the place. In the past the German name was Trifail.