Bridget Marquardt (born Bridget Christina Sandmeier; 25 September 1973) is an American television personality, model, and actress. She is best known for her role on the reality television series The Girls Next Door, which depicts her life as one of Playboy magazine publisher Hugh Hefner's girlfriends. Although not a Playboy Playmate, she has appeared in nude pictorials with her Girls Next Door costars and fellow Hefner girlfriends Holly Madison and Kendra Wilkinson.

Marquardt was born in Tillamook, Oregon after her family moved there from Lodi, California. Shortly after her birth, Marquardt's mother moved the family back to California, where Marquardt was raised. Her parents divorced when Marquardt was in the fifth grade. Her mother remarried, and Marquardt and her younger brother Edward moved to their stepfather's ranch, where they later gained a half-sister, Anastasia. Marquardt attended Galt High School for her freshman and sophomore years and then transferred to Lodi High School from which she graduated in 1990.

Hollin Sue Cullen, professionally known as Holly Madison, (born December 23, 1979) is an American model, showgirl and television personality. She is widely known for being one of Hugh Hefner's girlfriends on the reality television series The Girls Next Door. Madison now has her own reality series Holly's World.

Although not a Playboy Playmate, she has appeared in nude pictorials with her Girls Next Door costars, Bridget Marquardt and Kendra Wilkinson. In 2009, she appeared as a contestant on the eighth season of Dancing with the Stars.

Madison was born in Astoria, Oregon. She has one younger sister, Stephanie, and a younger brother, Joe. Both siblings were featured on season 3 and season 4 episodes of "The Girls Next Door." Her father's work in the timber industry led her family to travel. From ages two through eleven, she lived on Prince of Wales Island, near Ketchikan, Alaska. Her family later moved back to Oregon, this time to St. Helens. She attended Portland State University for two years, majoring in both theater and psychology.

Hugh Marston "Hef" Hefner (born April 9, 1926) is an American magazine publisher, founder and Chief Creative Officer of Playboy Enterprises.

Hefner was born in Chicago, Illinois, being the elder of two sons born to Grace Caroline (née Swanson; 1895–1997) and Glenn Lucius Hefner (1896–1976), both teachers. Hefner's mother was of Swedish descent and his father had German and English ancestry. On his father's side, Hefner is a direct descendant of Plymouth governor William Bradford. He has described his family as "conservative, Midwest, Methodist." He went to Sayre Elementary School and Steinmetz High School, then served as a writer for a military newspaper in the U.S. Army from 1944 to 1946. He later graduated from the University of Illinois at Urbana Champaign with a B.A. in psychology with a double minor in creative writing and art in 1949, earning his degree in two and a half years. After graduation, he took a semester of graduate courses in sociology at Northwestern University but dropped out soon after.

Cara Zavaleta (born June 15, 1980; Bowling Green, Ohio) is an American model and actress.

Zavaleta was a cast member of MTV's reality show Road Rules during the Road Rules: South Pacific season. During the season, she was voted off by her team and replaced by Tina Barta.

Cara was originally cast as part of the alumni team in 2007 Road Rules: Viewer's Revenge, but dropped out before filming began. She was replaced by Susie Meister. She has also participated on several of Real World/Road Rules Challenges including Real World/Road Rules Challenge: The Gauntlet, Real World/Road Rules Challenge: The Gauntlet 2, and Real World/Road Rules Challenge: The Inferno III.

After her stint on Road Rules, she posed for Playboy, becoming a Playboy Playmate.

Zavaleta is of mixed Mexican and Caucasian descent. On December 23, 2010, Zavaleta announced on her official YouTube page that she and her boyfriend are expecting their first child together, a boy due at the end of March 2011. She has moved back to Chicago, Illinois to be closer to her family.

Kendra Leigh Baskett (née Wilkinson; born June 12, 1985), professionally known by her maiden name, is an American television personality and glamour model. She is widely known for being one of Hugh Hefner's three girlfriends and for her role on the E! reality television series The Girls Next Door, on which her life in the Playboy Mansion was documented.

Although not a Playboy Playmate, she has appeared in three nude pictorials with her Girls Next Door costars and fellow Hefner girlfriends Holly Madison and Bridget Marquardt. Her own reality series, Kendra, debuted in June 2009.

Kendra Wilkinson is of Irish, Ukrainian, and English descent. She is the elder of two children; her younger brother is Colin. Her mother, Patti, was originally from Cherry Hill, New Jersey, and had been a cheerleader for the Philadelphia Eagles. Her father, Eric, was raised in Bryn Mawr, Pennsylvania, and Ocean City, New Jersey, before moving to San Diego, California at age 15. He received a degree in biochemistry from the University of California, San Diego, and went on to found several biotechnology companies before retiring at the age of 48. Patti and Eric married on November 5, 1983. They divorced on March 25, 1994, when Kendra was eight. Her grandmother Gloria Wilkinson died in December 2004.