Maggie Horton Kiriakis is a fictional character from the American Peacock/NBC network soap opera Days of Our Lives played by Suzanne Rogers since 1973, the longest running role on the show, and one of the longest running in American soap operas.

The character was created by scriptwriter William J. Bell and producer Betty Corday as a romantic interest for original character Mickey Horton (John Clarke). For her work as Maggie, Rogers won the Daytime Emmy Award for Outstanding Supporting Actress in a Drama Series in 1979.

Maggie's storylines often focus on romance and family troubles. She is portrayed as a stoic, opinionated, and family-oriented woman who is generally loving and supportive, but occasionally interferes in her friends' and relatives' lives. A prominent storyline in 1984 included Maggie discovering that she had Myasthenia Gravis, which mirrored Rogers' real-life struggles with the disease. In 2003, Maggie was killed off in a "whodunnit?" murder storyline involving a serial killer. Rogers returned to the show in 2004 after producer James E. Reilly decided to have all the murder victims turn up alive on the island of Melaswen, or "New Salem" spelled backwards.

Maggie's most well-known relationship was her longtime marriage to original series character Mickey Horton. The characters met during Rogers' first episode in 1973, when Maggie cared for him while living on a farm. Following a series of experiences together, the pair grew extremely close, and their bond became central to both characters until Mickey's death in 2010. The character has been described as a "legend" and a television icon.

Introduced as Maggie Simmons, Maggie is one of the earliest characters created by scriptwriter William J. Bell and executive producer Betty Corday. The character was brought on as a potential love interest for original character Mickey Horton. Shortly after, the two were married, connecting her to the soap's core family. Maggie is the mother of Melissa Horton (whom she adopted), Summer Townsend, Daniel Jonas, Janice Barnes (whom she fostered), and Sarah Horton. She has six grandchildren: Nathan Horton (via Melissa), Mackenzie Horton and Victoria Kiriakis (via Sarah), Melanie Jonas, Holly Jonas, and Parker Jonas (all via Daniel).

Suzanne Rogers auditioned for the role on July 13, 1973, and garnered the attention of future daytime legend, Susan Flannery, who played Dr. Laura Horton. Maggie was introduced as a guest character in August 1973, by scriptwriter William J. Bell and executive producer Betty Corday. From the beginning, Bell considered the role ideal for Rogers, a former Rockette from the Radio City Music Hall and Broadway chorus girl in such musicals as "Coco" and "Follies". Bell approached Rogers about taking the role of Maggie, and she agreed. She was immediately described by critics who gave reviews of the show as being one of the most energetic girls on daytime television. The news of Rogers being cast as Maggie was a different move, taking an actress who loves to dance, to a character of a crippled farm girl. This was her first television assignment, after being the youngest girl to take the stage at Radio City Music Hall.

In 1984, Rogers was diagnosed with a rare muscle disorder called Myasthenia Gravis. This disease affected her facial muscles and the medication she needed made her feel ill, with her face appearing swollen while also suffering hair loss. Rogers temporarily left the show after 11 years when the effects of the disease became increasingly worse. Her entire appearance changed, and she did not return to the show for a year. Rogers, wanting to educate viewers about the disease, approached executive producer Betty Corday about her character being diagnosed with the disease. Corday agreed, and a storyline played out with Maggie learning she has myasthenia gravis. The actress went into remission in 1995, and has remained in remission since. In 2010, Maggie began to notice some symptoms of the disease returning.

While limited attempts to give Maggie and Mickey storylines were made, for over a decade, they were relegated to supporting status, often off the front burner and with relative little airtime. Maggie was made more of a confidant to other major characters and often was written as the town busy-body, although an environmental plot twist had Maggie making her five star restaurant Salem's first "green" establishment. In 2003, a major series of serial killings occurred on the show. Maggie was "killed off" in a "whodunnit?" murder storyline involving a serial killer. Maggie's murder forced Rogers to depart from the series. To help with falling ratings at the time, head writer James E. Reilly decided to bring all the characters back from the dead. They all turned up in the fictional town of Melaswen, or New Salem spelt backwards. This storyline sparked major controversy, and proved to be a daring move.