A field research was carried out to study the effect of foliar applied seaweed extract on the growth and yield of radish cultivars. Research was conducted at horticulture research farm, the university of Agriculture, Peshawar, in winter during radish growing season, 2021. Experiment was laid out in Randomized Complete Block Design (RCBD) with split plot arrangement having two factors and three replications. Two factors included levels of seaweed extract (0, 5 mlL-1, 10 mlL-1 and 15 mlL-1) in main plot and radish cultivars (Mino early, green neck, red long and forty days) in subplot were studied. Analysis of variance revealed that foliar application of seaweed extract significantly affected growth and yield attributes of radish cultivars while their interaction was observed non-significant for all the studied parameters. Maximum vegetative growth and the highest root yield were observed for radish crop when 15 mlL-1 of seaweed extract was sprayed on plants. However, most of the growth and yield attributes at 15 mlL-1 were at par with those recorded at 10 mlL-1 of seaweed extract. Radish plants sprayed with 15 mlL-1 of seaweed extract produced the highest number of leaves plant-1 (15.93), leaf length (37.71 cm), leaf area (301.67 cm2), leaf chlorophyll content (37.7 SPAD), root length (39.41 cm), root diameter (6.20 cm), root weight (465.34 g), TSS (6.350 Brix) root moisture content (95.16%) and root yield (29.98 tons ha-1). Seaweed extracts application also reduced days to harvest. Minimum days to harvest (51.44 days) were observed at 15 mlL-1 of seaweed extract. All attributes, however, were observed inferior for the crop of radish in the control plots. Among radish cultivars, maximum number of leaves plant-1 (15.60), leaf area (298.05 cm2), leaf chlorophyll content (37.7 SPAD), root length (38.01 cm), root diameter (5.93 mm), root weight (462.47 g), root moisture content (96.10%) and root yield (29.55 tons ha-1) were recorded for cultivar Mino early which were at par with those recorded for green neck and red long while maximum TSS (6.300 Brix) was recorded for cultivar red long. Cultivar, forty days took minimum days to harvest (47.23 days) among all other studied cultivars of radish. Considering the stimulatory effects of seaweed extract on plant growth, yield and high benefit cost ratio, 15 mlL-1 of seaweed extract as a natural plant growth stimulant could be sprayed to improve vegetative growth and root yield of radish crop. Further, radish cultivar Mino early, is recommended for obtaining high yields and maximum profit under the agro climatic conditions of Peshawar.