Which production company made Downton Abbey for ITV?

Carnival Films made Downton Abbey for ITV.

The British production company Carnival Films produced the television series, which premiered on ITV in 2010. Julian Fellowes created and wrote the drama, while Carnival developed the production with ITV and international partners, including Masterpiece in the United States. Its involvement continued across all six series and later expanded to the Downton Abbey feature films.

Carnival Films was established in London in 1978 and became known for high-profile British television dramas. Its other projects include adaptations and series such as Poirot, The Last Kingdom, and Endeavour. The company later became part of NBCUniversal, helping Downton reach a large international audience while ITV remained its UK broadcast home.

The distractors are other respected British television companies, but they did not produce Downton Abbey. Mammoth Screen is associated with productions including Poldark, Kudos made series such as Spooks and Broadchurch, and Left Bank Pictures produced The Crown. Carnival Films is therefore the specific production-company answer, not the broadcaster or the US presenting brand.