Background: The importance of Diversity in Data was highlighted by the UK Health Data Research Alliance (The Alliance). It was acknowledged that improving data quality and increasing representativeness of data used for research and innovation is crucial for both custodians/collectors of data and researchers, to ensure that research is of high quality and based on complete data with the ultimate aim of improving patient outcomes. A working group was set up to discuss, understand and potentially address concerns relevant to the quality of available data, missingness, accessibility and harmonisation of data, which can hinder the reliability of scientific insights. While there are many different aspects to consider within the diversity data field, this working group focuses on challenges and opportunities in the use of data reporting ethnicity. To start the conversations, we are convening the community to share insights from ongoing work and understand the gaps that should still be addressed. This workshop report summarise the main points highlighted during the meeting