The 2020 Maryland Democratic presidential primary took place on June 2, 2020, after being rescheduled due to the COVID-19 pandemic, as one of eight delayed and regular primaries on the same day in the Democratic Party primaries for the 2020 presidential election. It was originally planned to take place on April 28, 2020, as one of several states in the "Acela primary". The Maryland primary was a closed primary, with the state awarding 120 delegates to the 2020 Democratic National Convention, of whom 96 were pledged delegates allocated on the basis of the primary results.

Presidential primaries and caucuses were organized by the Democratic Party to select the 3,979 pledged delegates to the 2020 Democratic National Convention held on August 17–20 to determine the party's nominee for president in the 2020 United States presidential election. The elections took place in all 50 U.S. states, the District of Columbia, five U.S. territories, and through Democrats Abroad, and occurred between February 3 and August 11.