The Court ruled in a narrow 4-3 vote that the map's boundary lines violated a 2018 measure passed by voters that gave map drawing authority to a commission in hopes of circumventing the practice of gerrymandering.
The ruling comes just two days after the same court decided against legislative district lines on the same basis, according to The Hill.
"The evidence in these cases makes clear beyond all doubt that the General Assembly did not heed the clarion call sent by Ohio voters to stop political gerrymandering," Justice Michael Donnelly wrote on behalf of the majority.
Had the maps been approved, at least 12 of Ohio's 16 congressional districts would have favored Republicans while Democratic voters would be pushed into just three districts.
"It's time for the state legislature to put aside partisan interests and prioritize the needs of Ohio voters. It is time for legislative leaders to put aside their personal partisan interests and create truly fair and representative maps that reflect Ohio," Catherine Tucker, executive director of Common Cause Ohio said in a statement. "The manipulation of districts is the manipulation of elections and voters have had enough."
Ohio has historically been a battleground state in general elections, and isn't the only state with contested congressional maps.
For months, advocates have called for federal intervention to prevent changes to districts and election processes that disproportionately restrict access to the ballot for Black, Latino, Indigenous, and low income voters.