The Qualitative Election Study of Britain (QESB) Party Leader Evaluation Database 2010 – 2019 contains 4,119 words and phrases that evaluate British political party leaders. The data were collected during pre-election focus groups and interviews conducted with participants from England, Scotland and Wales, during the General Election campaigns of 2010, 2015, 2017, and 2019. For the party leader evaluation pre-election component, participants were provided with head shot pictures of the party leaders (depending on where in Britain they lived) taken from the party’s own website. They were instructed to write down words or phrases they associate with each person, and indicate if that association was positive, negative or neutral. The data structure mirrors data structures used in sentiment analysis. Each tab contains a column listing participant’s’ words and phrases as a string variable; the next two columns list the election year and leader, affective evaluations (relating to, arising from, or influencing feelings or emotions) as a string variable, and the affective evaluation as a numeric scale from negative –1 to positive +1. These data are suitable for sentiment and discourse analysis, or analytic generalization – establishing that a concept exists within a population regardless of the number of people who hold it. In addition, a supplementary dataset is provided of leaders’ evaluation data from a study with residents of Dundee after the Scottish Independence Referendum in 2014 (N = 287).