#1 Best Private Schools in New Castle County, DE
St. Andrew's School
Episcopal school · Grades 9–12
One of the 3 largest Christian schools in Delaware
Middletown, DE
A+Overall grade320 students6 students per teacher
2026 lists
Best Private Schools in New Castle County, DE
Private schools in New Castle County, DE with the highest overall grades. Top 27 of 27 schools.
#2 Best Private Schools in New Castle County, DE
The Tatnall School
Independent school · Grades Pre-K–12
One of the 3 largest independent schools in Delaware
Wilmington, DE
A+Overall grade457 students6 students per teacher
#3 Best Private Schools in New Castle County, DE
St. Annes Episcopal School
Episcopal school · Grades Pre-K–8
One of the most diverse private schools in Delaware
Middletown, DE
A+Overall grade256 students7 students per teacher
#4 Best Private Schools in New Castle County, DE
Padua Academy
Diocesan school · Grades 9–12
100% of graduates go to four-year colleges
Wilmington, DE
A+Overall gradeAll girls424 students11 students per teacher
#5 Best Private Schools in New Castle County, DE
Ursuline Academy, Lower
Independent Catholic school · Grades 3–8
Smaller classes than 73% of Catholic schools in Delaware
Wilmington, DE
A+Overall grade456 students8 students per teacher
#6 Best Private Schools in New Castle County, DE
St. Edmond's Academy
Independent Catholic school · Grades Pre-K–8
Smaller classes than 64% of Catholic schools in Delaware
Wilmington, DE
A+Overall gradeAll boys158 students9 students per teacher
#7 Best Private Schools in New Castle County, DE
St. Anthony of Padua Grade School
Diocesan school · Grades Pre-K–8
One of the most diverse private schools in Delaware
Wilmington, DE
A+Overall grade161 students9 students per teacher
#8 Best Private Schools in New Castle County, DE
Harvest Christian Academy
Christian school (nondenominational) · Grades Pre-K–12
One of the most diverse private schools in Delaware
New Castle, DE
A+Overall grade94 students8 students per teacher
#9 Best Private Schools in New Castle County, DE
St. Peter Cathedral School
Parish school · Grades Pre-K–8
The smallest classes of any Catholic school in Wilmington
Wilmington, DE
A+Overall grade65 students6 students per teacher
#10 Best Private Schools in New Castle County, DE
Islamic Academy of Delaware
Islamic school · Grades Pre-K–8
The largest of 13 private schools in Delaware
Newark, DE
A+Overall grade124 students5 students per teacher
#11 Best Private Schools in New Castle County, DE
The Independence School
Independent school · Grades Pre-K–8
One of the 3 largest independent schools in Delaware
Newark, DE
AOverall grade384 students8 students per teacher
#12 Best Private Schools in New Castle County, DE
Centerville Layton School
Independent school · Grades K–12
Smaller classes than 91% of independent schools nationwide
Wilmington, DE
AOverall grade88 students3 students per teacher
#13 Best Private Schools in New Castle County, DE
Newark Center for Creative Learning
Alternative school · Grades K–8
Smaller classes than 61% of independent schools nationwide
Newark, DE
AOverall grade73 students7 students per teacher
#14 Best Private Schools in New Castle County, DE
Urban Promise School
Christian school (nondenominational) · Grades Pre-K–12
Smaller classes than 69% of Christian schools in Delaware
Wilmington, DE
AOverall grade85 students6 students per teacher
#15 Best Private Schools in New Castle County, DE
Red Lion Christian Academy
Christian school (nondenominational) · Grades K–12
The largest of 25 Christian schools in Delaware
Bear, DE
AOverall grade695 students10 students per teacher
#16 Best Private Schools in New Castle County, DE
Aquinas Academy
Independent Catholic school · Grades K–12
The only Catholic school in Bear
Bear, DE
B+Overall grade75 students9 students per teacher
#17 Best Private Schools in New Castle County, DE
Fairwinds Christian School
Baptist school · Grades Pre-K–12
One of the most diverse private schools in Delaware
Bear, DE
B+Overall grade173 students12 students per teacher
#18 Best Private Schools in New Castle County, DE
Concord Christian Academy
Baptist school · Grades Pre-K–12
The largest Christian school in Wilmington
Wilmington, DE
B+Overall grade136 students9 students per teacher
#19 Best Private Schools in New Castle County, DE
Caravel Academy
Independent school · Grades Pre-K–12
The only independent school in Bear
Bear, DE
B+Overall grade1,120 students10 students per teacher
#20 Best Private Schools in New Castle County, DE
Harvest Christian Academy New Castle
Christian school (nondenominational) · Grades Pre-K–12
One of the most diverse private schools in Delaware
New Castle, DE
B+Overall grade100 students9 students per teacher
#21 Best Private Schools in New Castle County, DE
St. Mary Magdalen School
Parish school · Grades Pre-K–8
One of the 3 largest Catholic schools in Delaware
Wilmington, DE
B+Overall grade467 students13 students per teacher
#22 Best Private Schools in New Castle County, DE
St. Mark's High School
Diocesan school · Grades 9–12
The largest of 15 Catholic schools in Delaware
Wilmington, DE
BOverall grade829 students17 students per teacher
#23 Best Private Schools in New Castle County, DE
St. Elizabeth School
Diocesan school · Grades Pre-K–12
One of the most diverse private schools in Delaware
Wilmington, DE
BOverall grade364 students12 students per teacher
#24 Best Private Schools in New Castle County, DE
St. Ann School
Parish school · Grades Pre-K–8
Serving families in Wilmington since at least 2011
Wilmington, DE
BOverall grade200 students16 students per teacher
Grades compare each school's official facts, such as class size, how long it has served families and where graduates go, with similar schools. They're a starting point: visit, ask questions and trust what you see.