This chapter analyses the origins of a range of consonantal features in MUE. Starting with an overview of the consonant system and a comparison of it to the consonant systems of the input varieties and to those of Ulster Scots and Southern Irish English, the chapter specifically concentrates on a number of key phonological patterns, several of them previously ascribed to Irish influence, which reveal crucial things about the history of the dialect. Features examined include Velar Palatalisation, Pre-R Dentalisation, survival of the dental fricatives, rhoticity, realisation of /l/, epenthesis in consonant clusters, and consonant deletions. It is shown that most consonantal patterns in the dialect derive from English and, to a lesser extent, Scots, possibly with some reinforcement from Irish.