Noson Lawen is a long-running Welsh-language television series, first broadcast on S4C in Wales in 1982.

The term Noson Lawen translates roughly into English as A Merry Evening. The programme takes the form of a variety show, with performers including singing duets, sketches, choirs, comedians etc. and with a different host every week. Presenters have included Gillian Elisa, and guests include not only Welsh-speaking performers like Dafydd Iwan, Robin Huw Bowen and John Ogwen, but international stars such as the quartet bond. Originally the show had a different host each week, but is now regularly presented by either Mari Lovgreen or Eleri Siôn.

In the show's early years the audience were seated on straw bales, with the various performances taking place on a farm trailer. Today the show is recorded in various indoor locations throughout Wales.