Climate change effect and adaptation measure on the livelihood deeds of artisanal Fishermen was carried out within the coastal areas of Southwest Nigeria. Multi-stage sampling technique was used to select 263 fishermen from Lagos, Ogun and Ondo States. Information obtained was with the use of structured interviewed schedule and subjected to descriptive and inferential statistics at 0.05 level of significance. Findings shows that majority (65.4%) of the Fishermen were between 45-64 years of age, 77.9% married, 67.7% had above 11 years of fishing experience across the Coastal area of Southwest, Nigeria. Also, 22.4% of Fishermen in the coastal area have access to extension services while 22.4% of them only had access to extension services. Major livelihood activities were fishing gathering (95.1%), fish processing (91.6%) and fish marketing (81.7%) in the selected area. the main effect of climate change on the fishermen activities were flooding (x̄= 2.43), while increased waves were (x̄ = 2.24), ocean surge (x̄ =2.23), rainfall intensity (x̄ = 2.07) and high temperature (x̄ = 2.06) respectively across the selected states respectively. Majority of the artisanal Fisherfolk utilized different adaptation measures/practices towards climate change. There were significant relationship (p < 0.05) between the respondent sex ( 2 = 19.342, df = 1), educational level ( 2 = 11.242, df = 4), ethnicity ( 2 = 10.523) and climate change effect on livelihood deeds of artisanal Fishermen across selected states. Correlation result also reveals significant relationship (p < 0.05) between age (r = 0.872), household size (r = 0.653), years of fishing experience (r = 0.815) and the climate change effect on livelihood activities of artisanal Fishermen across selected States, Results also showed that there is significant difference in the effect of climate change on livelihood of artisanal Fishermen (F = 16.325; P = 0.001) across the selected states. The study realized that Artisanal Fishermen sampled experienced high effect of climate change in term of flooding, increased waves, ocean surges, rainfall intensity and high temperature across the selected States sampled. The study recommended that Artisanal Fishermen should be participating in policy and strategy formulation in mitigate climate change impacts on their fishing and livelihood activities so as to reduce the vulnerability of the effects caused by climate change in the coastal areas.