The nomination comes nine days after government troops and paramilitaries cracked down on protesters outside army headquarters in Khartoum, killing more than 110 and wounding hundreds over several days.
Booth, 65, knows the country well, having served as the Obama administration's special envoy to Sudan and South Sudan over 2013-2017.
State Department spokesperson Morgan Ortagus said Booth is already at work, traveling with Assistant Secretary of State for African Affairs Tibor Nagy to Sudan "to engage with the parties."
Between 2005 and 2013, Booth served as US ambassador to Liberia, Zambia and then Ethiopia.
As special envoy to the two Sudans, Booth visited Khartoum numerous times and helped maintain a measured level of relations with the regime of president Omar al-Bashir, who was under indictment for genocide by the international criminal court.
Bashir's ouster by the military on April 11 after three decades of strongman rule sparked a nationwide movement calling for a civilian government.
But talks on the composition of a new governing body broke down and on June 3 the military launched a bloody assault on thousands of protestors, drawing international indignation.
The UN Security Council strongly condemned the attacks on civilians.
On June 5, Washington likewise criticized the violence, calling on Sudan's military leaders to "desist from violence" and agree to "a civilian-led transition that leads to timely elections and free expression of the will of the Sudanese people."
Nagy was headed to Khartoum to press the military on those demands.
But the administration of President Donald Trump was under pressure to do more.
Senator Cory Booker, who is seeking the Democratic nomination to run for president in 2020, wrote to Secretary of State Mike Pompeo last week demanding he name a special envoy for Sudan and an ambassador in Khartoum - a post currently vacant.
"In light of the severe political turmoil in Sudan, I write to urge you to appoint a Special Envoy for Sudan and South Sudan to bring urgently needed US diplomatic leadership to international efforts to address the crises in the two countries and to pursue sustainable peace in and between the two Sudans," Booker wrote.
Hollywood star George Clooney, known for advocacy for relief for Darfur and Sudan, on Tuesday called for the United States to lead the international community in tracking the financial assets he alleged had been plundered for years from Sudan's government and economy by Bashir's generals.
"Al-Bashir might be out of power, but the same regime still rules," Clooney wrote in Politico.
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