Mediation as a tool in conflict resolution in Africa has got its successes and failures. The successes of the process, though, has depended on the acceptability of the mediators by the warring parties, the neutrality of the mediators in the process, the funding given to the process by the lead actors and the skill and knowledge of mediators on the causes of conflict, the parties, process and viability of the product of mediation. In the case of South Sudan, Since December 2013 when IGAD started the mediation processes over the two warring factions, it has failed to formulate an enforceable ceasefire agreement or a negotiated political settlement thereby compounding on the problems bedeviling the people. This study therefore sought to evaluate the efficacy of the mediation process championed by IGAD. The objectives of the study were to examine the actors involved in the mediation process in conflict resolution in South Sudan; evaluate the efficacy of the actors in the mediation process in conflict resolution in South Sudan; establish the possible effective mediation processes for conflict resolution South Sudan. The research design to be employed by this study will be mixed method research methodology which is a combination of qualitative and quantitative research tools to collect data necessary for this study. The study was a case study of South Sudan. The researcher used both primary and secondary data which was obtained from analysis and review of books, journals, papers and other available literature on mediation process and conflict resolution in South Sudan. Data was then be analyzed using content analysis. Content analysis becomes a more powerful tool when combined with research methods such as interviews, records. The study established that there are various actors in the mediation process in South Sudan. They include IGAD as the lead mediator, regional states (Uganda, Kenya, Ethiopia), the AU and the international community such as the Troika and the US, the European Union, UN and China. The involvement of immediate regional actors in peace talks was a double-edged sword. Some of the major factors that has limited IGAD’s mediation process includes: regional rivalries and power struggles; centralisation of decision-making at the HoS level and related lack of institutionalisation within IGAD; and challenges in expanding the peace process beyond South Sudan’s political elites. The study recommends that, two things need to happen if peace is to be realized in South Sudan. First, there is a need to show that IGAD is no longer a neutral and credible body to promote peace in South Sudan. Second the government of South Sudan must not delegate its responsibilities of searching for peace in the country to others. It needs to take full responsible and device a way forward to end the rebellion in the country. The study also recommends that African countries and institutions, that is, IGAD, the IGAD Plus Five, the AU Peace and Security Commission, the AU Commission, have to be united and firm in enforcing this agreement on the parties. Moreover, additional security must be provided to protect the proposed government of national unity and the reform process, as well as civilians caught up in the war.