Transformation of agriculture and natural resources for sustainable development towards industrial economy in Tanzania, inter alia, relies on the quality of population. Health has always remained a very essential determinant of quality of a population. Evidently, attaining optimal health calls for collaboration between humans, animals and environmental health professionals plus understanding consequences of humans, animals and environment interactions on health. Attaining good health faces numerous challenges, health literacy (HL) inclusive. Despite, HL being a predictor of health outcomes, health care costs and utilization, yet, it is not empirically known to which extent most countries, Tanzania inclusive, have made efforts in terms of research and interventions in this important variable. A cross sectional study was conducted in Morogoro urban and Mvomero districts in Morogoro, Tanzania to specifically (i) assess HL, (ii) determine factors associated with HL, (iii) identify research efforts and interventions on HL in Tanzania. . Data were collected through a structured questionnaire from 1440 respondents obtained using multistage sampling procedure. HL was measured using One Health Literacy Assessment tool. Quantitative data were analysed using IBM-SPSS (v20) and Gretl software. The results revealed that 36.3% of the respondents had inadequate HL, 30.8% with Marginal HL and Adequate HL standing at 32.9%. Pearson coefficient correlation revealed HL correlating to group of attitudes (r = 0.135, p = 0.01), levels of engagement in health-related discussion (r = 0.609, p < 0.05), health behaviour categories (r = - 0.648, p = 0.05) and category of information seeking (r = 0.753, p = 0.05). Scanty empirical evidence exists on having HL researched and documented adequately in Tanzania. Having observed low HL and scanty research efforts and interventions on HL, efforts should be strengthened to promote HL under One Health Approach, given its importance towards realization of optimal health for humans, animals and the environment.