A field experiment was conducted during kharif 2025 at Main Agricultural Research Station (MARS), University of Agricultural Sciences, Raichur, Karnataka, to evaluate the effect of post-emergent herbicides application on growth, yield and fibre quality of Bt cotton (hybrid SWCH 4749 BG II). The experiment was laid out in a Randomized Complete Block Design (RCBD) with ten treatments and three replications. The treatments comprised four doses of pyrithiobac sodium 10 % + clethodim 10.25 % SE (160, 202.50, 243 and 283 g a.i. ha-1), clethodim 25 % EC, pyrithiobac sodium 10 % EC and pyrithiobac sodium 6 % + quizalofop ethyl 4 % MEC, each applied at 3-4 leaf stage of weeds followed by intercultivation at 45 DAS, along with weed-free check, a weedy check and farmer’s practice. The weed-free check recorded significantly higher growth parameters, yield attributes and seed cotton yield (2975 kg ha-1) and was on par with farmer’s practice (2750 kg ha-1). Among the herbicidal treatments, pyrithiobac sodium 10 % + clethodim 10.25 % SE @ 283 g a.i. ha-1 recorded significantly higher plant height (152.4 cm), sympodial branches (26.0 plant-1), leaf area (118.79 dm2 plant-1), total dry matter production (398.68 g plant-1), bolls (25.2 plant-1), boll weight (5.76 g) and seed cotton yield (2680 kg ha-1). These values were statistically on par with pyrithiobac sodium 10 % + clethodim 10.25 % SE @ 243 g a.i. ha-1 (2630 kg ha-1) and pyrithiobac sodium 6 % + quizalofop ethyl 4 % MEC (2532 kg ha-1). The weedy check recorded the lower values for all these parameters, including a seed cotton yield (1263 kg ha-1). The quality parameters viz., fibre length, fineness and bundle strength were not significantly influenced by the herbicide treatments.