Rebecca Gratz (March 4, 1781 - August 27, 1869) was an American educator and philanthropist, born in Philadelphia, Pennsylvania. She was a promoter of religious, educational and charitable institutions.

Gratz was elected as secretary of the Female Association for the Relief of Women and Children in Reduced Circumstances in 1801. She soon saw the need for an institution for orphans in Philadelphia and she was among those instrumental in founding the Philadelphia Orphan Asylum in 1815. Four years later she was elected secretary to its Board. She continued to hold this office for forty years. Under Gratz' auspices a Hebrew Sunday-school was started and she became both its superintendent and president, resigning in 1864. Gratz was also one of the founding members of the Female Hebrew Benevolent Society around November 1819. In 1850 she advocated in The Occident, over the signature A Daughter of Israel, for the foundation of a Jewish foster home. Her advocacy was largely instrumental in the establishment of such a home in 1855. Other organizations that came about due to her efforts were the Fuel Society and the Sewing Society .

Gratz is said to have been the model of Rebecca, the heroine of the novel Ivanhoe by Sir Walter Scott. Scott's attention had been drawn to Gratz' character by Washington Irving, with whom she was acquainted. The claim has been disputed, but it has also been well sustained in an article entitled The Original of Rebecca in Ivanhoe, which appeared in The Century Magazine, 1882, pp. 679-682.