The 89.7 percent graduation rate for New Jersey students was topped only by Iowa, which saw 90.8 percent of its students graduate from high school within four years of starting ninth grade.
High school graduation rates are difficult to compare because each state has different requirements for graduating from high school. New Jersey is in the minority of states that require students to pass exit exams in math and English before they can graduate.
Regardless, New Jersey's graduation rate consistently ranks among the highest in the nation and has increased by 6 percentage points since 2010-11.
"We are proud to be national leaders in graduating high school students," acting state Education Commissioner Kimberley Harrington said. "It is a testament to the hard work of our school communities."
Graduation rates are also climbing nationwide. The country's 83.2 percent graduation rate in 2014-15 was the highest since the 2010-2011 school year, the first year all states began calculating their graduation rate in the same way.
The new data shows improvement among every group of students, including white, African American, Hispanic, Asian and Native American students.
Low-income students, students with disabilities and students learning to speak English as their second language also posted higher graduation rates in 2014-15, though they still lagged compared to the national average.
The Obama administration touted the higher rates as progress toward preparing students for college and careers after graduation.