Vu Ðình Long (19 December 1896 - 14 August 1960) was a Vietnamese dramatist noted for the first western style spoken play in Vietnamese - A cup of Poison in 1921.
The Western-influenced style of "théâtre parlé" (k?ch nói) was a departure from traditional Vietnamese theatre.
Long's play Chén thu?c d?c was performed on the Hanoi Opera House stage on the evening of October 20, 1921.
The play was performed by the Van hóa (Culture) drama company.
Vu Ðình Long, like the younger Nam Xuong, adopted western techniques, but retained an idealization of Vietnamese patriarchal life.
In 1943 Long joined the H?i Van hóa C?u qu?c - the National Salvation Culture Society.