Bayugan, officially the City of Bayugan, is a 1st class component city in the province of Agusan del Sur, Philippines. According to the 2020 censu…Bayugan, officially the City of Bayugan, is a 1st class component city in the province of Agusan del Sur, Philippines. According to the 2020 census, it has a population of 109,499 people.. Gained cityhood through Republic Act No. 9405, it is the only city in the province of Agusan del Sur and also the most populous.