Outside of their immediate localities, has anyone ever heard much about Dennis Sidebottom, Louise Smith, J. Joseph Whelan, Camerino Lopez or Princess Whitfield? Probably not.

Each of them was recognized in a heartening report from the U.S. Department of Education on the teaching of ''disadvantaged'' children. Ordinarily in this capital of euphemisms, ''disadvantaged'' is taken to mean ''black'' or ''Hispanic.'' In this report the adjective is used precisely. The report addresses the needs of children who are in fact culturally disadvantaged: they are poor.

The thrust of the report is altogether positive. Secretary of Education William Bennett is convinced that children from the slums, ghettos and barrios can learn -- provided they are given opportunities and encouragement. Teaching such children may be demanding. But impossible? No.

Bennett introduces us to Dennis Sidebottom. In 1981 he became principal of tiny Carrizozo High School in Carrizozo, N.M., an isolated ranching community in an area of chronic high unemployment. He inherited an apathetic faculty and an uninterested student body. The school was characterized by absenteeism and vandalism. Sidebottom set out to make the school respected, and he succeeded. Today 97 percent of the students win their diplomas; 40 percent go on to college.

Louise Smith became principal of Charles Rice Elementary School in Dallas three years ago. Of the school's 850 students, 99 percent are black and nearly all come from low-income families. She decided to concentrate on skills in reading and math. Teachers tutor daily after school; children are encouraged to stay for a homework center where they get individual help. Today 73 percent of the sixth-graders are at or above grade level in reading, 87 percent are at or above grade level in math.

Chambers Elementary School in East Cleveland, Ohio, has 726 students. All of them are black; three-quarters live in poverty, and two-thirds are from single-parent families. For the past 18 years J. Joseph Whelan has been working devotedly with this unlikely material. He demands discipline. Without apology he promotes old-fashioned patriotism. At the front door is the school's motto: ''To Achieve Excellence, Think Excellence.'' In a dozen ways Whelan recognizes and rewards good work.

Camerino Lopez has been principal of Garfield Elementary School in Phoenix, Ariz., for the past five years. Ninety-nine percent of her 800 students come from low-income households. More than half are Hispanic. This means a bilingual kindergarten, followed by intensive instruction in English from the second through the sixth grades. Parents and local businesses contribute time and money. The school's attendance rate of 96 percent is the highest in the district.

Here in Washington, Hine Junior High School used to be known as ''Horrible Hine.'' Bennett's report accurately describes the situation in 1982: ''Enrollment had plummeted from 1,000 students to 296. Drugs were openly used, vandalism was rampant, and academic achievement poor.'' Instead of closing the school, as a community task force had recommended, the board of education named Princess Whitfield as principal and gave her the assignment of turning the place around.

''Her plan for action included strict discipline and security policies, active parental and community involvement, and the introduction of a rich curriculum that would hold the attention of all students.''

Today Hine's enrollment has passed the 700 mark; its curriculum includes Latin and ''Great Books.'' Vandalism and drug use ''have virtually ceased.'' School spirit has soared, and it is ''Horrible Hine'' no longer.

The moral to all these stories is not only that top-notch principals can make top-notch schools. What is required to turn poor schools into good schools is parental and community support and a determination that the job will be done. Bennett's report provides a hundred specific suggestions toward that end. Upward of 12.5 million poor children are out there, and half of them are scoring in the bottom quarter on achievement tests. They need all the help they can get.