Thiri Maya Dewi Mi U-Si (Burmese: သီရိမာယာဒေဝီ မည်ဦးစည်, pronounced [θìɹḭ màjà dèwì mì ʔú sì]^{[note 1]}) was a principal queen of King Razadarit of Hanthawaddy Pegu from 1392 to 1421.

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According to the Razadarit Ayedawbon chronicle, the queen was the youngest daughter of Saw Ye-Bein, a senior minister at the Hanthawaddy court. Her personal name was Mi U-Si (မည်ဦးစည်). She had two elder sisters Mwei Ohn-Naung and Mwei Auk^[1] In April 1392, she became a senior queen of King Razadarit, with the title of Thiri Maya Dewi (Pali: Sirimāyādevī). Her two sisters were also raised as queens at the same ceremony.^[1]

She and her sisters were first cousins once removed of the king. Their father was a first cousin of Razadarit. Their paternal grandfather Binnya Thein was a noble from Chiang Mai who after a disagreement with the king of Chiang Mai had sought refuge at the court of King Binnya U. Their paternal grandmother was Tala Saw Lun, a daughter of King Saw Zein.^[2]