These data and analyses support the research article "How and Why We Travel - Mobility Demand and Emissions from Passenger Transport (O'Riordan et al., 2022). This article refers to a spreadsheet model, the Irish Passenger Transport Emissions and Mobility Model (IPTEM V2.9). The spreadsheet model is available for download from Zenodo (O'Riordan et al., 2022). The model and the underlying data, details the passenger transport demand by trip purpose (work, shopping, education etc.,), mode type (car, rail, bus, cycling, walking) and trip distance for Ireland over the period of 2009-2019. Passenger occupancy rates for public transport modes in Ireland, CO2 emissions intensities and annual CO2 emissions are also included in the Data in Brief. Assumptions and equations used to develop the IPTEM V2.9 are available in the Experimental design, materials, and methods section.