Kidder, one of five children, was born in Yellowknife, North West Territories, the daughter of Jocelyn Mary "Jill" (née Wilson), a history Teacher, and Kendall Kidder, an explosives expert and Engineer. Kidder also spent time growing up in Labrador City, Newfoundland and Labrador. Her mother was from British Columbia, Canada, and her father was from New Mexico, United States. She is of Welsh and English descent. Kidder was born in Yellowknife because of her father's job, which required the family to live in remote locations. Her father was manager of the Yellowknife Telephone Company from 1948 to 1951. Kidder recalled her childhood in northern Canada, saying, "We didn't have movies in this little mining town. When I was 12 my mom took me to New York and I saw Bye Bye Birdie, with people singing and dancing, and that was it. I knew I had to go far away. I was clueless, but I [have done] okay."