Rachel Lloyd (January 26, 1839 – March 7, 1900) was an American chemist who studied the chemistry and agriculture of sugar beets (Beta vulgaris).

On October 1, 2014, the Society designated her research and professional contributions to chemistry at the University of Nebraska-Lincoln a National Historic Chemical Landmark.

Rachel Abbie Lloyd (née Holloway) was born in Flushing, Ohio, to Quaker parents Robert Smith Halloway and Abigail Taber.

In 1863, the couple moved to Bangor Township, Bay County, Michigan, where Franklin managed a saw mill, salt works and barrel factory for lumber merchants in Philadelphia.

Rachel Lloyd inherited a sum of money, which she used to travel Europe from 1867–1872, seeking medical help for rheumatism and neuralgia.

Lloyd supported herself for some time as a science teacher at the Chestnut Street Female Seminary before making the decision to formally pursue her interest in chemistry.

[1] In 1884, Lloyd enrolled in the University of Zurich, which at the time was the only institution where women were permitted to complete a doctorate in chemistry.

[6] Lloyd began teaching immediately after finishing her early education at Miss Margaret Robinson's School for Young Ladies.

Her next teaching position would be at the Chestnut Street Female Seminary in 1873, where she taught chemistry following her travels in Europe.

In 1880, Lloyd served as the Lady Principal of Foster School for Girls in Clifton Springs, New York.

[9] The findings of Lloyd and Nicholson's work resulted in investors opening up the third sugar refinery in the United States in Nebraska.

After her death, Acting Chancellor Charles E. Bessey said in a memorial lecture at the University of Nebraska, "She was not only an eminent chemist, she was a great teacher, and more than that, she was the beloved advisor and counselor of students".

[9] Lloyd died on March 7, 1900, in Beverly, New Jersey[10] due to heart failure and was buried with her husband and children in Laurel Hill Cemetery in Philadelphia.