Yaxun Büalam III (also known as 6-Tun-Bird-Jaguar) was a high king of the Mayan city Yaxchilan from 631 until 681.
Yaxun Büalam's father was Küinich Tatbu Skull III. The name of his mother is unknown.
Yaxun married Lady Pacal (sister of Lady Xoc), and their son, Itzamnaaj Büalam III, succeeded him as king.
It is generally believed that Büalam is the third Yaxun Büalam; "6-Tun" was later added to the glyph of his name, distinguishing him from his grandson, Yaxun Büalam IV (also known as Bird Jaguar IV).
Büalam ruled Yaxchilan from 631 to 681.
On the stairs of Temple 33, he is depicted as being on the eighth step playing ball on the date August 27, 636.
In either 646 or 647, Büalam captured a lord from the Hix Witz polity, a Maya center. He noted the capital of the Hix Witz polity was located at Zapote Bobal during that time.