The dearth of information about the fabrication of flexible polyaniline and graphite-based microporous and low-cost thermoelectric generators using screen printing for low-temperature applications has motivated us to undertake this research work. Polyaniline and graphite composite inks were formulated using cellulose acetate as resin and diacetone alcohol as the solvent. In this work, we have studied the influence of ink ingredients on the thermoelectric properties of composite inks. Diacetone alcohol improved the electrical conductivity of polyaniline by 7.9 times. The carrier concentrations and carrier mobility of composite ink were enhanced by 2.8 times. Simultaneously, cellulose acetate increased resistivity and carrier mobility of polyaniline by 13 and 44 times, respectively. Graphite improved the crystallinity but reduced carrier mobility, carrier concentration, and bandgap of the composite inks. Screen-printed porous ink film structure reduced the thermal conductivity of PANI ink by 11 times at 333 K. The maximum Seebeck coefficient and power output exhibited by the fabricated thermoelectric generator were 244.34 μV/K and 4.31 nW, respectively at 77 K. Present work explored fabrication and characterization of low cost, flexible polyaniline and graphite composite ink-based thermoelectric generator with improved Seebeck coefficient and power output for low-level heat energy conversion. •Polyaniline/graphite ink-based flexible thermoelectric generator is screen printed.•Cellulose acetate resin improved resistivity and carrier mobility of polyaniline.•Diacetone alcohol solvent enhanced electrical conductivity of polyaniline.•Graphite in polyaniline reduced carrier concentration, mobility, and bandgap.•The porous leg thermoelectric generator produced a power output of 4.31 nW at 77 K.