[2] Born at Marshfield, Coos County, Oregon,[3] to John Stephen and Mary E. Coke, he was the grandson of Sterling and Caroline Cocke and a great-grandson of Revolutionary War participant William Cocke.

He began his practice in Wailuku, Maui and in 1908 was elected as a county attorney.

Coke moved to Honolulu in 1909, represented Oahu in the Territorial Senate in 1912, and became circuit court judge in 1916.In 1912 he also fathered with Henrietta Amoy Ahlo, an illegitimate son, James Anthony Tokunaga (adopted) whom James L. Coke never recognized.

[2] In 1917, President Woodrow Wilson appointed Coke as an associate justice to the territorial supreme court, and in 1918 Wilson elevated Coke to chief justice, which office he held until 1922.

In 1935, Coke was again appointed chief justice by President Franklin D. Roosevelt, retiring from that position in 1941.