This study focused on the impact of strategic management and sports competition on sustainable growth and development of grassroots sports in Southwest, Nigeria. Descriptive research method was adopted for this study. The population of this study comprised all grassroots sports personnel of the States Sports Commission/Council and amateur athletes in Southwest, Nigeria. Four hundred and sixty-three (n = 463) respondents were selected from four (4) State Sports Commissions/Councils; Lagos, Ogun, Osun and Oyo States of Southwest Nigeria, using Multistage sampling technique. The instrument used were adapted Strategic Planning and Management Questionnaire (r = 0.82) and Sports Development Scale (r = 0.75). The data collected was analyzed using Multiple Regression to determine the level of significance between the two hypotheses and observed values at 0.05 alpha level. The two null hypotheses generated for the study were rejected while the alternate hypotheses were accepted. The result of the study revealed that strategic management and sports competition have significant impact on sustainable growth and development of grassroots sports in Southwest, Nigeria. The study recommended that strategic management and sports competition approach should be adopted by grassroots sports managers to bring about sustainable sports development and ensure productive grassroots sports management practices.