Before signing the bill on Tuesday, Reeves said he disagrees with the removal of statues through the country, but "I also understand the need to commit the 1894 flag to history and find a banner that is a better emblem for all Mississippi", reports Xinhua news agency The state's lawmakers on Sunday overwhelmingly voted to replace the flag as protesters across the country demanded a reckoning to systemic racism following the death of black man George Floyd in police custody on May 25.
A commission will design a new flag that does not include the Confederate symbol broadly condemned as racist, said local media reports, and the new design will go before voters in November for approval.
The state flag, adopted in 1894, nearly 30 years after the end of the Civil War, is the last in the US to feature the Confederate battle emblem.
The flag was originally used by the slave-owning states who lost the US Civil War (1860-65).
African-Americans make up for 38 per cent of Mississippi's population.
Hundreds of statues dedicated to the Confederacy - the southern states which revolted against the US government - exist all throughout the US, and often serve as an reminder of the history of slavery and racial oppression in the country.