The work highlights the bioconvective transport phenomena of gyrotactic microorganisms in Maxwell nanofluid passing over an inclined plate enclosed in Darcy–Forchheimer porous medium. The medium is stratified in terms of heat, mass, and motile density gradient and under the influence of an inclined magnetic field. The physical situation is well described by means of governing partial differential equations. Under some capable similarity transformations, the governing equations are remodeled into the system of ordinary differential equations and worked out numerically using Runge–Kutta–Fehlberg technique. The consequences of pertinent flow properties on temperature, nanoparticle volume fraction, and motile microorganisms density distributions are illustrated graphically. Also, the main curiosity is focused to realize the changes in important quantities of engineering interest owing to the alteration in crucial parameters. It is revealed that the dominancy of the Marangoni ratio and Maxwell fluid parameter on motile microorganism gradient accelerates with a higher magnetic effect. Further, the thermophoretic effect plays a remarkable role in the reduction of motile microorganism transport with a smaller Brownian motion effect.