The R&D sector is one of the important economic phenomena in terms of competitiveness and innovation performance. The aim of the study is to examine the impact of selected R&D indicators on the economic activity of EU countries with emphasis on economic growth and employment in knowledge-intensive service sectors in 2011-2021. The research was carried out using panel data analysis (the fixed effects method) for three models of EU countries (EU27 countries as a whole and EU27 countries divided into two groups according to their innovation performance). The results in the evaluated years confirmed the different (positive/negative) impact of the examined R&D indicators on economic growth and employment in knowledge-intensive service sectors between the different groups of EU countries. In the “Innovation Leaders and Strong Innovators” countries, high-tech exports had the largest positive effect on GDP per capita, and general government expenditures had the largest negative effect. The largest negative effect of government expenditures on tertiary education was found in the case of Employment in knowledge-intensive service sectors. By contrast, in the case of GDP per capita and employment in knowledge-intensive service sectors, the largest negative effect of government expenditures on tertiary education and the positive effect of research and development expenditures were found in the “Moderate Innovators and Emerging Innovators countries”. The findings may be useful for both makers of selected public policies and R&D practitioners in evaluating economic analysis.