This is a detailed list of performances by County Louth athletes in major international track & field championships. The list includes performances in global, continental and Commonwealth events at senior level both outdoors and indoors.

It includes athletes who were members of a Louth club at the time of the performance, as well as former members of Louth clubs who would generally be regarded as being "originally from" County Louth, regardless of which country they were representing at the time.