Aims: With the rising concerns about indiscriminate use of chemical fertilizers and accumulation of agro-industrial wastes in huge quantities, the present experiment was conducted to elucidate the effect of a novel fungal strain of Trichoderma atroviride in hastening the compost/vermicompost production process and for the production of humic acid (HA) rich compost and vermicompost. Methods and Results: Rice (Oryza sativa) straw and distillation waste of geranium (Pelargonium graveolens), two important agricultural/industrial crop wastes were subjected to composting and vermicomposting. T. atroviride strains GVF10 (cellulase and xylanase producing), and RVF3 (ligninase and celluloxylanase producing) were inoculated alone or in combination. The HA content was found to increase maximally in rice vermicompost treated with ligninase producing strain RVF3 (85% with respect to HA standard) followed by geranium vermicompost + RVF3. The addition of the strain GVF10 increased HA content to about 35-62% with respect to HA standard. The addition of the fungal inoculum reduced the composting/vermicomposting time from 110 to 90 days. Conclusions: Our results indicate that the use of selected fungal strain(s) hold potential to produce qualitatively superior compost and vermicompost with high HA content in a shorter period. Significance and Impact of the Study: Use of appropriate fungal strains may increase the efficiency of composting/vermicomposting processes producing compost and vermicompost with higher HA content, and alleviating the problems of solid waste accumulation and declining soil fertility.