The purpose of this study was to investigate the effects of Webquest learning strategy on the citizenship education learning outcomes of pre-service teachers in colleges of education in South-western Nigeria. The study adopted a quasi-experimental research design with a pretest-posttest control group. Intact classes of pre-service teachers were used in purposively selected two federal and two state colleges of education spread over the South-western states of Nigeria. In Oyo State, the Federal College of Education (Special}, Oyo (experimental group) made use of intact classes of pre-service teachers taught with the use of Webquest while the College of Education, Lanlate (control group) made use of the conventional strategy. In Ogun State, Federal College of Education, Abeokuta was the experimental group, while Tai Solarin College of Education, Ijebu-Ode was used as the control group. Data were collected using a Citizenship Education Learning Outcomes Test (CELOT) and analysed using descriptive and inferential statistics. The findings showed that the pre-service teachers in the experimental group have significantly higher mean scores on the CELOT. Also, the results revealed that the Webquest learning strategy had a significant effect on the pre-service teachers’ cognitive and affective learning outcomes in citizenship education. The study recommended that using Webquest strategy in teaching citizenship education concepts enable pre-service teachers acquire the environmental concepts and improve their level of achievement instead of depending only on the conventional method. Also, it draws the attention of the Federal Ministry of Education and the National Commission for Colleges of Education to the importance attached to employing Webquest strategy in teaching citizenship education concepts