The aim of this research project is to investigate how effective influencer marketing is for growing sports clothing brands in Ireland. The researcher used a concurrent mixed method research design, combining survey and grounded theory research strategies to conduct an interview and also an internet questionnaire. The purpose of the interview was to gain rich insights from an influencer marketing professional to understand how effective influencer marketing can be for growing sports brands in Ireland. For the internet questionnaire, the researcher aimed to further investigate how effective influencer marketing is by testing a hypothesis while also testing two further hypotheses to examine the effects it is having on sports clothing consumers in Ireland. The results suggest that the majority of the target population are following influencers online and would be willing to buy what they promote. In addition to this, the results suggest a cross-media synergy exists between influencer marketing and offline sales channels. Finally, influencer marketing can be a highly effective communication tool for growing sports brands, however the strategy implemented still needs to align with the brands objectives and capabilities.