Wheat (Triticum aestivum L.), a staple food crop is of great commercial importance. Its production is restricted due to various abiotic stresses. One major abiotic stress is terminal heat stress, which is considered the main wheat yield-limiting factor. Therefore, a field experiment was conducted to identify the terminal heat stress-tolerant genotypes among ten diverse wheat cultivars under timely sown (TS) and late sown (LS) conditions during the rabi season of 2018-2019 at the wheat research farm, Department of Genetics & Plant Breeding, CCS HAU, Hisar. Various physiological and biochemical attributes were evaluated by using a factorial randomized design with triplicates. Grain yield (g/m2) ranged from 435.4 to 537.8 and 243.0 to 396.5 under TS and LS conditions, respectively. The highest grain yield was observed in PBW821 (537.8) followed by RAJ3765 (529.1) and DBW14 (520.0) under TS while in PBW821 (396.5) followed by RAJ3765 (345.8) and DBW14 (344.0) under LS condition. Maximum photosynthetic rate (14.8 µmole·m-2·s-1), transpiration rate (6.59 mole·m-2·s-1), stomatal conductance (0.31 mmole·m-2·s-1), chlorophyll content (44.6), cell membrane stability (57.28%), and osmotic potential (1.07 MPa) were found in PBW821 under LS condition while in free radical scavenging activity, RAJ3765 (84.47%) was observed maximum under LS condition. The results indicate that PBW821, RAJ3765, and DBW 14 were identified as a thermo-tolerant that can be used in plant breeding programs and further lay the foundation for genetic analysis.