Moving forward three years, Diaz landed a major role in My Best Friend’s Wedding. Not only a global box office hit, the film is also widely regarded as one of the most popular romantic comedies of all times, with the actress starring alongside Julia Roberts, Dermot Mulroney and Rupert Everett.

Just the following year, the actress starred in the 1998 hit, There’s Something About Mary, as the titular role of Mary. Continuing her comedic roles, Diaz's character is a central part of the film, experiencing several men vying for her attention due to her irresistible "something".

Starring along Ben Stiller and Matt Dillon, the film became the highest-grossing comedy of 1998 in North America, as well as the fourth-highest-grossing film of the year. Diaz was nominated for a Golden Globe Award in the category of Best Actress – Musical or Comedy for her role.

In 1999 Diaz starred alongside John Cusack, Catherine Keener and John Malkovich in the now cult classic Being John Malkovich. 

In the film, Cusack plays a puppeteer who finds a portal that leads into Malkovich's mind, with the actress portraying the role of Lotte Schwartz, the the pet-obsessed wife wife of Craig Schwartz (Cusack). The film received widespread acclaim and was an arthouse success.

A continuation of the television series of the same name, in 2000, Diaz starred alongside Drew Barrymore and Lucy Liu as an elite crime-fighting team who work as private investigators together for unseen millionaire Charlie.

Though many of the gender stereotypes portrayed in the film don't quite hold up in 2021, at the time it still signalled that female-led action films could succeed, with Charlie’s Angels grossing over US$264 million worldwide.

Voicing the character of Princess Fiona, Diaz took her first foray into the world of animation in 2001––with the film becoming a family favourite spanning years to come.

Shrek grossed US$484.4 million worldwide and become the first movie to win the Academy Award for Best Animated Feature, with Diaz reprising her voice role for the three sequels.

Just a slight departure from Shrek and her previous roles, in 2002, Diaz starred in Martin Scorsese's epic historical drama film, Gangs of New York.

Alongside Leonardo DiCaprio and Daniel Day-Lewis, Diaz plays the role of the role of a pickpocket-grifter and the love interest of DiCaprio's character during the mid-19th century in the Five Points district of New York City.

Based on the novel of the same name by Jennifer Weiner, In Her Shoes focuses on the relationship of two jarringly different sisters and their grandmother. Starring with Toni Collette, Diaz takes the role of Maggie, a free-spirited wild child who moves in with her older and more serious sister Rose (Collette).

Who could forget The Holiday? Now a much-loved Christmas classic, the film tells the story of two women––Amanda (Diaz), an American movie trailer producer and British journalist (Kate Winslet)––who swap houses and lives during the holiday season.

Written and directed by Nancy Meyers, the rom-com is worth a re-watch for Diaz's wardrobe alone.