Harrier co-starred as Patrice Dumas, a civil rights activist, in the film BlacKkKlansman (2018) opposite John David Washington, Adam Driver, and Topher Grace.
The film premiered at the Cannes Film Festival in May 2018, where it won the Grand Prix, and was subsequently theatrically released in August 2018.
The director, Spike Lee, handpicked Harrier after seeing an audition tape she had done for another project.
She was on vacation in Greece when Lee demanded that she meet him in New York City for an audition, where he acted as her scene partner.
The next day, she was offered the role.
In preparation for it, Harrier met with activist Kathleen Cleaver and other women who were in the Black Power movement; studied Angela Davis; and contacted people who were in the Black Student Union at Colorado College during the 1970s.
She also spoke with her own father, who dealt with racism while living in South Side, and as the only black student at his boarding school in Michigan; his ancestors were slaves.
All of these people were Harrier's inspirations and influences for the role.
Harrier also attended several of Lee's classes at New York University where he is a film professor.
For her performance, Harrier received positive reviews, and was nominated for a Black Reel Award and a Screen Actors Guild Award.

In 2019, director Jamie Adams offered Harrier the lead role in his film Balance, Not Symmetry; she accepted the part due to the project being mostly improvised and being good friends with Bria Vinaite, her co-star in the film.
She plays Caitlyn Walker, an art student at the Glasgow School of Art, who is struggling with the recent death of her father.
The film was a critical failure.
Cath Clarke of The Guardian thought Harrier gave a "blank performance".

She starred in the Netflix miniseries Hollywood (2020) by Ryan Murphy as Camille Washington, an up-and-coming black actress facing prejudice during the Hollywood Golden Age in the post-World War II era.
Before booking her role, Harrier only knew that it was an untitled Old Hollywood project.
Months after her initial audition, she did a chemistry read with her on-screen boyfriend Darren Criss.
Harrier primarily drew inspiration for her role from actress Dorothy Dandridge, and to a lesser extent from singer and actress Lena Horne as well.
Both Dandridge and Camille were nominated for the Academy Award for Best Actress, but only Camile won it.
To prepare for the Academy Award scene, Harrier studied Halle Berry's acceptance speech at the 74th Academy Awards.
The series and Harrier's performance received mixed reviews, and some critics compared her performance unfavorably to her work in BlacKkKlansman.
Darren Franich and Kristen Baldwin from Entertainment Weekly thought she was "so charismatic in BlacKkKlansman", but remarked "there’s no sign of that fire here".
The Hollywood Reporter's Daniel Fienberg noted she "looks the part", but believed Camille was underdeveloped.
There were positive reviews including Gabriel Tate from the i newspaper who called her "heartbreakingly convincing".

On July 17, 2020, Harrier starred as the lead role, a young woman going through a breakup, in the music video for "What's Love Got to Do with It", the remix version by Kygo of the original Tina Turner song.

Harrier is set to star in Bios with Tom Hanks, which is scheduled to premiere on April 16, 2021, and in The Starling alongside Melissa McCarthy, which is set to premiere on Netflix.
Harrier co-starred as Patrice Dumas, a civil rights activist, in the film BlacKkKlansman (2018) opposite John David Washington, Adam Driver, and Topher Grace. The film premiered at the Cannes Film Festival in May 2018, where it won the Grand Prix, and was subsequently theatrically released in August 2018. The director, Spike Lee, handpicked Harrier after seeing an audition tape she had done for another project. She was on vacation in Greece when Lee demanded that she meet him in New York City for an audition, where he acted as her scene partner. The next day, she was offered the role. In preparation for it, Harrier met with activist Kathleen Cleaver and other women who were in the Black Power movement; studied Angela Davis; and contacted people who were in the Black Student Union at Colorado College during the 1970s. She also spoke with her own father, who dealt with racism while living in South Side, and as the only black student at his boarding school in Michigan; his ancestors were slaves. All of these people were Harrier's inspirations and influences for the role. Harrier also attended several of Lee's classes at New York University where he is a film professor. For her performance, Harrier received positive reviews, and was nominated for a Black Reel Award and a Screen Actors Guild Award. 
In 2019, director Jamie Adams offered Harrier the lead role in his film Balance, Not Symmetry; she accepted the part due to the project being mostly improvised and being good friends with Bria Vinaite, her co-star in the film. She plays Caitlyn Walker, an art student at the Glasgow School of Art, who is struggling with the recent death of her father. The film was a critical failure. Cath Clarke of The Guardian thought Harrier gave a "blank performance".
She starred in the Netflix miniseries Hollywood (2020) by Ryan Murphy as Camille Washington, an up-and-coming black actress facing prejudice during the Hollywood Golden Age in the post-World War II era. Before booking her role, Harrier only knew that it was an untitled Old Hollywood project. Months after her initial audition, she did a chemistry read with her on-screen boyfriend Darren Criss. Harrier primarily drew inspiration for her role from actress Dorothy Dandridge, and to a lesser extent from singer and actress Lena Horne as well. Both Dandridge and Camille were nominated for the Academy Award for Best Actress, but only Camile won it. To prepare for the Academy Award scene, Harrier studied Halle Berry's acceptance speech at the 74th Academy Awards. The series and Harrier's performance received mixed reviews, and some critics compared her performance unfavorably to her work in BlacKkKlansman. Darren Franich and Kristen Baldwin from Entertainment Weekly thought she was "so charismatic in BlacKkKlansman", but remarked "there’s no sign of that fire here". The Hollywood Reporter's Daniel Fienberg noted she "looks the part", but believed Camille was underdeveloped. There were positive reviews including Gabriel Tate from the i newspaper who called her "heartbreakingly convincing".
On July 17, 2020, Harrier starred as the lead role, a young woman going through a breakup, in the music video for "What's Love Got to Do with It", the remix version by Kygo of the original Tina Turner song.
Harrier is set to star in Bios with Tom Hanks, which is scheduled to premiere on April 16, 2021, and in The Starling alongside Melissa McCarthy, which is set to premiere on Netflix.
Laura Harrier