The aim of this research investigation was to determine whether tactical differences could be found between male and female rugby union lineouts in the 2017/18 ‘Six nations’ Competition. The investigator analysed 30 games that took place during the Men’s and Women’s ‘Six Nations’. The ‘Six Nations’ consists of six northern hemisphere international teams, Wales, France, Italy, Ireland, Scotland and England. These nations have been anonymised throughout the results and discussion section of the investigation, team names were replaced with pseudonyms. The research study determined the tactical differences between men and women during lineouts, a number of variables that exist within a lineout were investigated, such as; Lineout Numbers (7 Man, 6 Man, 5 Man, 4 Man, Quick), Lineout Option (First man, Front, Middle, Back, Over the Top), Lineout Option 2 (Off the Top, Drive, Down and Give, Other) Field Position that the lineout took place (TL-22, 22-HW, HW-22, 22-TL) and First Phase Outcome. The results of this investigation show that there are no significant lineout variables that show a tactical difference between male and female lineouts in rugby union. Despite this, there are some narrow percentile differences that can be seen between the genders.