'To Kill a Mockingbird' is written by -

To Kill a Mockingbird, a novel by Harper Lee, published in 1960.
Enormously popular, it was translated into some 40 languages and sold more than 30 million copies worldwide.
In 1961 it won a Pulitzer Prize. The novel was praised for its sensitive treatment of a child’s awakening to racism and prejudice in the American South.
Source: Britannica.com