A mathematical model based on the Susceptible-Exposed-Infected-Recovered (SEIR) for hepatitis B is formulated. Existing clinical hepatitis B data was obtained from the unit of health information management in the department of medical records, Federal Medical Centre, Keffi in formulating the mathematical model to fathom the transmission dynamics in keffi LGA. This will aid in preventing, controlling and eradicating the disease and improve lives in the LGA. The LGA was assumed to have a constant population size. The 2006 population figure of Keffi was used to validate the model. Sensitivity and simulation analysis were performed on the model equation using Microsoft Excel to determine the effect of different parameter values on the spread of the disease. The algorithm was implemented using maple. It was proved that the global dynamics were completely determined by the basic reproductive number R₀. If R_{0 <}1, the disease-free equilibrium is globally stable and the disease always die out. And if R_0>1, an endemic equilibrium exists and is globally stable in the interior of the feasible region, and the disease remain at an endemic equilibrium state if it at the outset exist. The result shows that about 10.61% of the susceptible population should be vaccinated in order to bring the spread of hepatitis B under control in the LGA (study area).