Leah Messer is an American reality television personality best known for her long-running role on MTV's Teen Mom 2, a series that documented the lives of young mothers navigating parenthood, relationships, and personal growth. She first came to national attention through the second season of 16 and Pregnant, which chronicled her pregnancy and the early days of motherhood, before becoming one of the original four cast members of Teen Mom 2 when it premiered on January 11, 2011.

On Teen Mom 2, Messer's storylines centered on raising her twin daughters, her evolving relationships with family and partners, and the personal and financial struggles that came with being a young mother. Alongside fellow cast members Jenelle Evans, Chelsea DeBoer, and Kailyn Lowry, she became a familiar face to MTV audiences across more than a decade of the series. The show highlighted the changing dynamics between family, friends, and boyfriends while underscoring the challenges faced by young women raising children.

Over the years, the cast of Teen Mom 2 shifted as the series evolved. In June 2017, Briana DeJesus joined the show, and in May 2019, following Jenelle Evans's departure, Jade Cline was added to the cast. Chelsea DeBoer announced her exit in October 2020 after ten seasons, and Ashley Jones was brought on to replace her that December. Messer remained part of the franchise through these transitions, making her one of the more enduring figures in the Teen Mom universe.

After the final episode of Teen Mom 2 aired on May 24, 2022, the series was merged with Teen Mom OG into a combined program titled Teen Mom: The Next Chapter, which premiered on September 6, 2022. Messer continued her involvement with the franchise through this new iteration, extending a television career that has spanned well over a decade.

Beyond her reality television work, Messer has been open on camera about the personal challenges she has faced, including health concerns and family matters, which have been central themes in her storylines. Her willingness to share these experiences has made her a recognizable and frequently discussed figure among fans of the Teen Mom franchise.