Baghdad wants to boost economic and political relations with neighboring countries and increase investment to develop its dilapidated infrastructure and revamp the economy battered by years of war, under-investment and sanctions.
Built in the early 20th century when Iraq was a British colony, the railway stopped after US troops toppled Saddam Hussein in 2003, plunging the country into violence.
"This will strengthen Iraqi-Turkish political and economic ties," Ender Saritekin, Turkey's deputy consul in Iraq's northern city of Mosul, said Wednesday.
After strained ties under Saddam, relations between Ankara and Baghdad have warmed. Last year, the countries signed deals from energy cooperation to water sharing.
The train, with 13 passengers on board, set off on Tuesday for an 18-hour journey from Mosul, 390 km north of Baghdad, to the southern Turkish city of Gaziantep, Akram Ahmed, head of railways in Iraq's northern region said.
The train service, which covers a distance of about 600 km and will also carry freight, will operate twice a week.
As part of a plan to revamp Iraq's train network, the Baghdad mayor's office said last year that it had short-listed eight foreign firms to build its first metro and expected the project to cost $3-$4 billion.
Iraq sends around a quarter of its oil exports, or around 500,000 barrels per day, from its north to the Turkish port of Ceyhan. Baghdad is trying to vault itself to one of the top three global oil producers after a series of crude deals.
