This thesis examines the impact of immigration on economic growth using quantitative analysis of data spanning from 1970 to 2021 across thirty countries with open trade relationships. The study aims to address two research questions to understand how immigration influences economic growth dynamics. Specifically, the main research question explores the overall impact of immigration on economic growth, while sub-research questions investigate specific mechanisms through which immigration contributes to GDP growth.The thesis employs regression analysis and panel data techniques to analyse the relationship between immigration and GDP growth. By excluding Great Britain from the dataset following its departure from the EU in 2020, the study focuses on understanding how immigration influences economic growth, and the findings are expected to provide insights into the varying impacts across the chosen countries.The study contributes to the existing literature by providing empirical evidence on the role of immigration in economic development, emphasizing factors such as labour force dynamics, innovation, and entrepreneurial activities stimulated by immigrant populations. Additionally, the thesis discusses the implications of immigration policies and demographic changes on economic outcomes, offering recommendations for policymakers to optimize the economic benefits of immigration.The analysis reveals complexities, including a negative correlation between aging populations and GDP growth, alongside mixed impacts of government expenditure on economic outcomes. A positive association between higher levels of net immigration and increased GDP growth, underscoring immigrants' pivotal role in driving economic expansion. Additionally, the study identifies correlations linking immigration to job creation, innovation, and entrepreneurship, highlighting immigrants' diverse contributions to economic development.These findings emphasize the nuanced interplay of immigration policies, demographic factors, and economic strategies, urging policymakers to consider these dynamics when fostering sustainable economic development strategies within the EU.