The purpose of this paper is to investigate the transmission dynamics of COVID-19 with Dengue coinfection using a mathematical model. The human population was divided into six compartments, while the mosquito population was divided into two sections. The model considers that COVID-19 infection might be symptomatic or asymptomatic. First, we analyzed the dengue infection model. The basic reproduction number of the COVID-19 infection system and the Dengue infection system are used to forecast illness mitigation and persistence (denoted by ℛ0C and ℛ0D respectively). The qualitative examination of the sub-systems indicated that the disease-free equilibrium (DFE) is locally asymptotically stable provided the corresponding reproduction numbers are less than one. The coinfection model is then analyzed to yield the basic reproduction number, designated by ℛ0. The DFE and stability of the coinfection model are dependent on ℛ0 = max {ℛ0D, ℛ0C}. The numerical simulation of the coinfection model showed the existence of the endemic equilibrium of the coinfection model. Furthermore, we studied the dynamic solutions of the coinfection model by establishing the equilibrium points and evaluated the stability requirements.