Earthworms (Oligochaeta: Clitellata) are widely recognized as soil ecosystem engineers due to their critical role in nutrient cycling, organic matter decomposition, and soil structure formation. Their distribution is strongly influenced by soil physicochemical properties, making them reliable bio-indicators of soil health and ecological integrity. Understanding the environmental determinants of earthworm diversity is particularly important in semi-arid regions, where soil fertility and biodiversity are vulnerable to salinity, nutrient imbalance, and land use pressures. This study investigated earthworm diversity and habitat suitability across six land-use types in Faisalabad, Pakistan, from May 2023 to April 2024. A total of 1,800 soil samples were collected monthly from urban, peri-urban, agricultural, and forested zones. Earthworms were hand-sorted, identified, and geo-referenced, while soil variables including pH, electrical conductivity (EC), total dissolved solids (TDS), nitrogen (N), phosphorus (P), potassium (K), organic carbon (OC), sodium (Na), calcium (Ca), lithium (Li), ash, and heavy metals were analyzed. Four species were identified, with Lumbricus trapezoides (48.8%) and Lumbricus rubellus (47.2%) dominating. Diversity indices (H′ = 0.75–0.83) indicated moderate diversity, while Green’s Index confirmed clumped spatial distributions. Principal Component Analysis (PCA) highlighted sodium and soil moisture as the strongest environmental drivers influencing species distribution. Species distribution models generated using MaxEnt v3.4.1 achieved moderate test performance (AUC = 0.765–0.871). Sodium, moisture, and organic matter emerged as the most influential predictors of habitat suitability. Overall, earthworm diversity and distribution in Faisalabad’s semi-arid agroecosystem are shaped primarily by soil ionic composition and moisture availability. These findings provide a valuable baseline for monitoring soil biodiversity and contribute to strategies aimed at enhancing soil health and sustainable agroecosystem development in semi-arid landscapes.