Over the course of the Second World War, almost three million American service personnel passed through the United Kingdom as part of the American “occupation” of the UK. The first 4,000 of these three million American GIs arrived in Northern Ireland in 1942 and the total number of GIs who passed through Northern Ireland would eventually reach 300,000. However, despite the fact that Northern Ireland was the first part of the United Kingdom to receive GIs, and was home to a considerable number during the Second World War, it is chronically under-examined in the existing literature. Northern Ireland and the experiences of American GIs stationed there during the Second World War deserves careful, deliberate consideration due to the distinct nature of Northern Ireland within the United Kingdom as a consequence of its geographical location, history, politics, and religious tensions. Making use of such sources as letters, interviews, and newspaper articles, and relying on recent academic research from Simon Topping, as well as older works from David Reynolds and Juliet Gardiner, this paper will seek to remedy the tendency to overlook Northern Ireland by providing an examination of the experiences of American soldiers stationed there during the first year of the American presence in 1942 and an analysis of the complicated position and history of Northern Island in relation to the rest of the United Kingdom. This paper concludes that the arrival of GIs in Northern Ireland set a precedent for the extension of the American “occupation” of the UK over the course of Second World War, and also considers how this experience can be linked to the development of Anglo-American relations and the expansion of U.S. military power in the world in the twentieth century.