In this paper, an investigation into Williamson nanofluid stagnation point flow of nano-biofilm over a stretching/ shrinking sheet with chemical reaction is performed. Moreover, the impact of cylindrical-shaped nanoparticles, activation energy, and bioconvection has been considered. The fluid’s fluctuating transport properties (dynamic viscosity, heat conductivity, nanoparticle mass diffusivity) and microorganism diffusivity are evaluated. The nonlinear systems of partial differential equations are transformed into nonlinear differential equations via the implementation of similarity transformations. The shooting approach and RK-4 technique are used for this investigation. The impacts of various fluid transport characteristics and various factors on patterns of velocity, temperature, the concentration of nanoparticles, and motile density are described. The Brownian motion, heat source and thermophoresis parameters all lead to a more consistent temperature profile being observed. It is seen that concentration-dependent properties decrease the velocity profile while the temperature, concentration, and motile density profiles increase. Also, the physical quantities decrease with the rising values of concentration-dependent properties.