A Grain of Wheat is a historical novel written by Kenyan novelist Ngũgĩ wa Thiong'o, first published as part of the influential Heinemann African Writers Series. It was written while he was studying at Leeds University and first published in 1967 by Heinemann. The title is taken from the Gospel According to St. John, 12:24.

The novel weaves together several stories set during the state of emergency in Kenya's struggle for independence (1952–59), focusing on the quiet Mugo, whose life is ruled by a dark secret. The plot revolves around his home village's preparations for Kenya's independence day celebration, Uhuru day. On that day, former resistance fighters General R and Koinandu plan on publicly executing the traitor who betrayed Kihika (a heroic resistance fighter hailing from the village).

In 2022, A Grain of Wheat was included on the "Big Jubilee Read" list of 70 books by Commonwealth authors, selected to celebrate the Platinum Jubilee of Elizabeth II.