Ohio Secretary of State Frank LaRose's office says the Minnesota senator filed the required paperwork on Monday. Elections officials still must verify her petitions.
Klobuchar was positioned as the most prominent Midwestern candidate in the field when she joined the race in February. She's now among 18 Democrats running for president in a field that's been growing as primary season nears.
This summer, Ohio lawmakers voted to move Ohio's primary to March 17, St. Patrick's Day. Democrats complained conflicting with parades and other holiday festivities could make voting and finding poll workers difficult.
The perennial swing state elected Republican President Donald Trump in 2016, after twice supporting Democrat Barack Obama.
Copyright 2019 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.