Grace Olivier Peck was born in Portland, Oregon, to Jules Olivier and Geneva Young in 1898. After her parents separated, she spent her childhood with her mother and at her grandfather's home in the Goose Hollow area of Portland. Many members of the extended family lived in Michigan. Peck's father was a steamboat pilot, and before his retirement in 1921, he sailed the Tanana and Yukon Rivers out of Fairbanks, Alaska. Her younger brother, Arthur, also lived and worked in Alaska. After graduating from Chapman School, Lincoln High School, and Behnke-Walker Business College, Peck worked as a legal secretary and stenographer for Portland attorneys Latourette and Latourette. She was then employed as a timekeeper in the Vancouver shipyards and served as shop steward for the office employees' union. She also worked in the real estate industry.

Peck married salesman Vernon Maxwell and lived for several years in San Francisco and Oakland, California. They returned to Portland in 1927 and separated in 1930. In 1936, she married Raymond Peck, a family friend. With her father, they moved into the house at 2324 SE Ivon Street, which Jules Olivier had purchased in 1914. Later, it was designated the Grace Peck House. The Pecks separated in 1941, and Grace Peck did not remarry.

Peck was first elected to the Oregon State Legislature in 1948 and served until 1950; she was elected again in 1956 and served through 1976. As a state legislator, Peck focused on improving conditions for disabled, poor, and incarcerated people, and an addition to the Women's Correctional Institute in Salem was named in her honor. She was defeated in the 1976 Democratic primary by W. Rod Monroe, who based his campaign mainly upon her age.

Peck was active in patriotic and Catholic groups, such as the Catholic Daughters of America and Ladies of the Grand Army of the Republic. She suffered an incapacitating stroke in 1977, and she died in 1979.