Soil bioinoculation with cyanobacteria has emerged as a sustainable biotechnological tool for improving soil fertility and physicochemical properties in dryland areas. This study evaluated the effects of inoculation with two individual terrestrial nitrogen-fixing cyanobacterial strains, Anabaena cylindrica and Nostoc punctiforme, as well as their consortium, on soil fertility, microbial biomass, and enzymatic activity. Completely randomized treatments of unplanted agricultural soil were conducted under greenhouse conditions. Soils were inoculated with fresh cyanobacterial biomass, either individually or as a consortium, and amended or not with organic (50% compost) or mineral fertilizer (50% NPK). Significant increases in surface soil total organic carbon (TOC), total nitrogen (N), available phosphorus (P), potassium (K), and calcium (Ca) were observed in treatments inoculated with the consortium alone or combined with fertilizers compared to individual strains and control. Higher improvements in soil fertility (TOC +410%, N +156.52%, P +119.04%, K +43.15%, Na +77.55%, and Ca +21.75%) correlated with the cyanobacterial consortium combined with 50% organic compost. This consortium has also significantly enhanced the biomass of soil microbial communities (cyanobacteria +244.44%, bacteria +257.5%, and fungi +140.92%), soil chlorophyll a content (+347.71%), and enzymatic activity (dehydrogenase +560.08% and alkaline phosphatase +66.82%) against the control. Principal Component Analysis (PCA) indicated that inoculation with the A. cylindrica and N. punctiforme consortium, either alone or combined with half dose of organic compost, was significantly correlated with improved soil fertility. These findings highlight that cyanobacteria-based consortia inoculants can improve soil fertility, support the viability of soil microorganisms, and ultimately promote plant growth and productivity.