She was born in Belgium, and her family included her missionary parents, four brothers and one sister. Elisabeth's brothers Thomas Howard and David Howard are also authors.

The family moved to Pennsylvania when she was a few months old. She has lived in Franconia, New Hampshire; Philadelphia, Pennsylvania; and Moorestown, New Jersey. She studied Koine Greek at Wheaton College, where she met Jim Elliot. Prior to their marriage, Elisabeth took a post-graduate year of specialized studies at Prairie Bible Institute in Alberta, Canada, where a campus prayer chapel is named in her honor. Jim Elliot and Elisabeth Howard went individually to Ecuador to work with the Quichua Indians; they married in 1953 in the city of Quito, Ecuador. Their daughter, Valerie (born 1955), was 10 months old when her father was killed. Elisabeth continued her work with the Quechua for two more years.

Two Huaorani women living among the Quichua, including one named Dayuma, taught the Huao language to Mrs. Elliott and fellow missionary Rachel Saint. When Dayuma returned to the Huaorani, she created an opening for contact by the missionaries. In October of 1958, Mrs. Elliot went to live with the Huaorani with her three-year-old daughter Valerie and Rachel Saint.

The Auca/Huaorani gave Elisabeth the tribal name Gikari, Huao for "Woodpecker." She later returned to the Quichua and worked with them until 1963, when she and Valerie returned to the US (Franconia, New Hampshire).

In 1969, Elisabeth married Addison Leitch, professor of theology at Gordon-Conwell Theological Seminary in Massachusetts. Leitch died in 1973. In 1977, she married Lars Gren, a seminary student who had been boarding at her house. The Grens later worked and traveled together.

In the mid-1970s she served as one of the stylistic consultants for the committee of the New International Version of the Bible (NIV). She appears on the NIV's list of contributors.

From 1988 to 2001, Elisabeth could be heard on a daily radio program, Gateway to Joy, produced by the Good News Broadcasting Association of Lincoln, Nebraska. She almost always opened the program with the phrase, "'You are loved with an everlasting love,' - that's what the Bible says - 'and underneath are the everlasting arms.' This is your friend, Elisabeth Elliot ..."

In the past few years, Mr. and Mrs. Gren have stopped traveling but continue to keep in touch with the public through mail and their website.