Maria Guyomar de Pinha, also Maria Guiomar de Pina, Dona Maria del Pifia, Marie Guimar or Madame Constance in French or Thao Thong Kip Ma (Thai: ท้าวทองกีบม้า) (Born in Ayutthaya in 1664), was a Siamese woman of the 17th century who lived in Ayutthaya, Siam (modern Thailand). She was the wife of the Greek adventurer Constantine Phaulkon.
Maria Guyomar was a Catholic woman of mixed Japanese-Portuguese-Bengali ancestry. Her mother was a Japanese, named Ursula Yamada, whose family had emigrated to Thailand following the repression of Christianity in Japan. Her father Fanik Guyomar (also Phanik Guimar), from the Portuguese colony of Goa, was a Christian of mixed Japanese and Bengali descent.
In 1682, Maria married Phaulkon, soon after he abandoned Anglicanism for Catholicism. They lived a life of affluence as Phaulkon rose to become highly influential at the Siamese court of king Narai.
During the period of rapprochement between France and the Siamese court Maria Guyomar de Pinha, together with her husband Phaulkon, was promised French protection by being ennobled a countess of France.