Ethel Marguerite de Long Zande (1879–1928) was an American educator from New Jersey who contributed to the settlement school movement of the early 20th century.

In 1912, de Long joined Pettit in leaving Hindman to establish the Pine Mountain Settlement School.

In 1913, de Long enlisted the help of the architect Mary Rockwell Hook to create a master plan for the new school.

De Long's network of women she had met while at Smith College also proved a useful base for fundraising and for hiring workers for the school.

[1] In April 1918, de Long married Luigi Zande, an Italian stonemason who had been working at Pine Mountain.