Background: Despite the importance of caregivers being trained in anaphylaxis management and the use of adrenaline auto-injectors (AAIs), studies have revealed inadequate caregiver knowledge. The caregiver anaphylaxis knowledge in an Irish population has not been previously assessed. This study aims to evaluate the anaphylaxis management knowledge and AAI administration proficiency among parents of children with food allergies. Methods: The parents of children with food allergies who were prescribed an AAI were invited to take part in a study involving online education. The participants completed an online questionnaire assessing anaphylaxis knowledge. They then took part in an online educational intervention where their AAI administration ability was assessed. Results: Out of a total score of 12, the mean anaphylaxis knowledge score was 9.76/12, SD 1.577, or 81.33%. Of the 152 participants, 26.7% (n = 40) performed all three critical AAI administration steps correctly. A household income under EUR 40,000 per annum reduced the likelihood of successful AAI administration (OR 0.33 95% CI 0.125–0.87, p = 0.025). Regarding the AAI devices, 46.4% claimed to have switched between devices at least once before. Conclusions: The parents demonstrated good knowledge of anaphylaxis management, but the prevalence of device switching underscores the importance of comprehensive AAI training. Future assessments should include evaluations of enhancements in knowledge, anxiety levels, and overall quality of life.