Sosban Fach (Welsh for "little saucepan") is a traditional Welsh folk song. It is one of the best-known and most often sung songs in the Welsh language.

The song is based on a verse written by 'Mynyddog' (Richard Davies) in 1873 as part of his song Rheolau yr Aelwyd ("Rules of the home") — see below. Talog Williams, an accountant from Dowlais, created the song we have today by altering Mynyddog's verse and adding four new verses. The song catalogues the troubles of a harassed housewife.

The song is associated with the rugby union club Llanelli RFC and, more recently, the Scarlets regional rugby side. The association derives from Llanelli's tin plating industry, which used to tin-plate steel saucepans and other kitchen utensils as a cheap supply to the British public. During the final years of Stradey Park, the former ground of Llanelli RFC and the Scarlets, the goalposts were adorned with Scarlet saucepans as a tribute to the town's history; the utensils have been transferred to the clubs' new ground, Parc y Scarlets. The Scarlets' official magazine is titled Sosban.

This song has been adopted by the fans of the rugby teams, Llanelli RFC and the Llanelli Scarlets. Many English variations can be heard in the stands during rugby matches.

After Llanelli beat a strong New Zealand side on 31 October 1972, a new English chorus could be heard:

Honouring the Llanelli RFC teams which beat the touring Australian national teams in 1908 and 1992, a further English chorus variation has been sung alongside the All Blacks verse:

Other variations include the following.

Dafydd James refers to a player who scored the winning points in a Heineken Cup match.