Charles Lewis Slattery (December 9, 1867 – 1930) was a bishop of the Episcopal Diocese of Massachusetts and a prominent writer in the early twentieth century. He was born in Pittsburgh, Pennsylvania to the Reverend George Sidney Leffingwell and Emma McClellan Slattery.
He was educated at Harvard University (1887-1891) and the former Episcopal Theological School (1891-1894) at Cambridge, Massachusetts. He was ordained to the diaconate in 1894 and to the priesthood in 1895. He served as dean of the Cathedral of Our Merciful Saviour in Faribault, Minnesota from 1896-1907; rector of Christ Church, Springfield, Massachusetts (1907-1910); and rector of Grace Church, New York (1910-1922).
Slattery was Bishop Coadjutor of the Episcopal Diocese of Massachusetts from 1922 to 1927, and diocesan bishop from 1927-1930. A prolific author, he received honorary doctoral degrees from the Episcopal Theological School, the University of the South at Sewanee, Trinity College, Hartford, and Harvard University.