Silvia Romano was 23 and working as a volunteer in the orphanage in Chakama village in south-east Kenya when she was seized by gunmen in November 2018.
“Silvia Romano has been freed!” Conte said in a tweet.
“I’d like to thank the women and men of the external intelligence services. Silvia, we look forward to seeing you in Italy!” he added.
Chakama is about 60km inland from the coastal town of Malindi, which is popular with Italian tourists and expatriates.
During the attack on Nov 20, 2018, the armed assailants shot and injured five people in the orphanage, including three children.
No details were released about Romano’s release, or about the identity or motivation of her captors.
“The state abandons no one,” Italian Foreign Minister Luigi Di Maio tweeted.
The kidnapping of foreigners is relatively rare in Kenya, but have had a damaging effect on the country’s crucial tourist economy.
A spate of abductions on the coast in 2011 saw a British man shot dead and his wife kidnapped from a resort island, while weeks later a French woman was taken from her home on the Lamu archipelago.
Soon afterwards Al-Shabaab gunmen abducted two Spanish aid workers from the Dadaab refugee camp close to the Somali border in the only confirmed case of kidnapping inside Kenya by the Muslim militants.
In April 2019, two Cuban doctors were kidnapped in northeastern Kenya and whisked to Somalia before US$1.5 million (S$2 million) was demanded for their release.
Kenyan police sources said the kidnapping bore the hallmarks of Al-Shabaab, a militant outfit that has been waging an insurgency against Somalia’s foreign-backed government for over a decade.