As a capital city, Cardiff has an important role in promoting Wales as a fully bilingual country. Cardiff has the fourth highest number of Welsh speakers out of the Local Authorities in Wales with the number of Welsh speakers in the capital city more than doubling over the last 25 years. The 2011 census indicated that 16.2% of people in Cardiff identified themselves as having one or more skills in the Welsh Language (53,680) with 11.1% of the population aged 3+ being able to speak Welsh (36,735). In 2016, 4,624 pupils are enrolled in Welsh-medium primary education and 2,625 at secondary level.

The number of people who can speak Welsh varies significantly across the city. For example, more than three times as many people are able to speak Welsh in Canton, Pentyrch and Creigiau/St Fagans compared to those living in Pentwyn, Rumney and Llanrumney.