"I will do everything I can to elect a Democratic President and a Democratic Senate in 2020," the Ohio Democratic senator said in a statement.
Sen. Sherrod Brown announced Thursday he will not run for president.
The surprise announcement comes after a two-month tour through early voting states, which many believed was the building blocks of a presidential campaign.
"I will keep calling out Donald Trump and his phony populism. I will keep fighting for all workers across the country. And I will do everything I can to elect a Democratic President and a Democratic Senate in 2020. The best place for me to make that fight is in the United States Senate," Brown said in a statement.