Increasing numbers of biosimilar medicines are becoming available. The objective of this survey was to assess awareness of and attitudes to biosimilars amongst physicians (medical specialists and General Practitioners (GPs)) and community pharmacists in Ireland. Physicians were invited to complete an online questionnaire during April and May 2016. Community pharmacists received a postal questionnaire in August 2015. Responses from 102 medical specialists, 253 GPs and 125 community pharmacists were analysed. The majority of medical specialists (85%) and pharmacists (77%) claimed to be either very familiar or familiar with the term biosimilar, whereas many GPs (60%) were unable to define or had never heard of the term. One in five (21%) healthcare professionals responded that biosimilars were the same as generic medicines. The majority of medical specialists opposed pharmacist-led substitution of biological medicines but some thought it could be appropriate if agreed with the clinician in advance. Medical specialists who prescribe biosimilars (n = 43) were more likely to do so on treatment initiation (67%), than switch a patient from an originator medicine to a biosimilar (28%). The findings will aid the design of educational initiatives for healthcare professionals and highlight attitudes of healthcare professionals to biosimilars, so informing regulators, policy makers and industry.