Buyan Suldus (died 1362) was chief of one segment of the Suldus clan of Taichuud tribe during the 1350s and 1360s, and was chief amir of the Chagatai ulus for a short time after 1358.

Although did not control the entire Suldus tribe, Buyan was its most powerful chief. He was the leader of the Suldus in Shadman and Chaghaniyan.

When the Qara'unas Amir Qazaghan killed Qazan Khan and took effective control of the Chagatai Khanate in 1346, his base of power was in the southern portion of the ulus; he mostly left the northern tribes alone. Despite the fact that the Suldus were considered a northern tribe, Buyan did cooperate with Qazaghan on occasion. During Qazaghan's punitive expedition against the Kartids in 1351, for example, he was the only leader of a northern tribe to participate. His attitude changed, however, when Qazaghan was killed in 1358 and was succeeded by his son, ‘Abdullah. ‘Abdullah wanted greater control over the northern tribes and, for this reason, moved his capital to Samarkand. Buyan resented having a strong Qara'unas presence near his territories and revolted. Together with Hajji Beg, the leader of the Barlas tribe, they overthrew ‘Abdullah and killed his puppet khan. Buyan then became amir of the ulus.