This study examinedthe effect of Greenhouse Gas emission (GHGD) and energy consumption disclosure (ECDI) on the market competitiveness of listed non-financial firms on the Nigerian Exchange Group (NGX).Market competitiveness was proxied using the market-to-book ratio (MTBR).The study anchored on two theories: 'agency theory' and 'stakeholder theory'. The expost facto research design was used and a purposive sample of thirty-eight non-financial firms listed on the NGX during the study period were selected as the sample. This study utilised secondary sources of data, from annual financial statements retrieved from the MachameRatios® database. The data were analysed using multiple regression techniques. The results showed a significant negative effect of the GHGD on MTBR (p=0.0164); while ECDI had a non-significant positive on the MTBR (p=0.1140) of listed non-financial firms. The study concludes that GHG emissions and energy consumption disclosure affect the market competitiveness of listed non-financial firms in Nigeria. The study recommends that management and boards of non-financial firms should strive for increased transparency and disclosure of Greenhouse Gas emissions by companies. Companies can enhance their reputation among environmentally conscious investors by disclosing their GHG emissions, demonstrating their commitment to sustainability and climate responsibility. The management of non-financial firms should improve the energy consumption disclosure of their activities. Companies can enhance investor trust and confidence by disclosing their energy consumption levels and providing valuable information about their operational efficiency and resource management practices