Lunden became one of the most visible women in the country when she joined "GMA" in the fall of 1976 as a consumer reporter. Entertainment Weekly magazine national viewer poll once named her "television's favorite morning anchor." She was a host on the A&E cable network program Behind Closed Doors (1996-2001) and has frequently guest hosted Biography.

Ms. Lunden has a liberal arts degree from Sacramento State, where she was initiated as a member of the Greek sorority Delta Gamma. She also studied Spanish and anthropology at Mexico City's Universidad de Las Americas. She was a visiting instructor at Montclair State College in New Jersey, where she taught a course in broadcast journalism

She began her broadcasting career in Sacramento, California, where she worked for KCRA-TV and Radio as co-anchor of the daily noon television news program. She also produced the noon news broadcast and hosted KCRA's television specials.

In 1975, she joined New York's WABC-TV Eyewitness News and a year later became co-anchor on the weekend newscasts.

As the co-host of GMA, Lunden traveled the world, covering historic events, such as the 50th anniversary of VE Day (Victory in Europe) in 1995; the 50th anniversary of D-Day; the 1984 and 1988 Winter Olympics in Sarajevo and Calgary; and the wedding of Prince Charles and Lady Diana. She covered the administrations and inaugurations of three Presidents: Bill Clinton, George H. W. Bush, and Ronald Reagan. She was one of only three American journalists to interview Prince Charles during his 1983 visit to the United States.

Lunden was known for her willingness to take risks in her role as host. She climbed and rappelled Alaska's famed Mendenhall Glacier and bungee-jumped off a 143-foot bridge and parapented off a 2,000-foot mountain during the program's highly rated trip to New Zealand. She also navigated the whitewater rapids of a Georgia river for a GMA show in 1994. She has been at the controls of an F-18 jet and soared with the United States Air Force Thunderbirds, as well as flown in a T-34 Naval flight training plane. She is also a skilled horsewoman, jumping thoroughbred horses, and also has gone to bat with the Chicago Cubs at spring training.

Lunden also hosted ABC's broadcast of the Tournament of Roses Parade in Pasadena, California, from 1989 to 1991.

She has received numerous honors including the Spirit of Achievement Award from Albert Einstein College of Yeshiva University, YWCA Outstanding Woman's Award Speaker, National Women's Political Caucus Award, New Jersey Division on Civil Rights Award and Baylor University Outstanding Woman of the Year. The National Mother's Day Committee selected her as the Outstanding Mother of the Year in 1982-83 for her dedication to motherhood. She has been a national spokesperson for MADD (Mothers Against Drunk Driving).

In April 1991, Lunden was honored by New York Women in Communications with a Matrix Award for her "outstanding contributions to the broadcasting field."

Lunden appeared as herself in a brief role in the 2006 film Thank You for Smoking.

She was married to Michael Kraus from 1978 until their divorce in 1992; the couple has 3 daughters. She married Jeff Konigsberg on April 18, 2000; they have 4 children, two sets of twins (each consisting of one boy and one girl, born in 2003 and 2005), both of which were delivered by Joan Lunden's surrogate mother, Deborah Bolig, in Cincinnati, Ohio.

Lunden sits on the Board of Trustees of the University of Pennsylvania in Philadelphia.