The Ministry of Defence confirmed that 21 personnel from 1st Battalion The Royal Irish Regiment arrived in the Malian capital Bamako on Tuesday.
Six members of The Irish Defence Force arrived on the same aircraft.
They will be joined by troops from 45 Commando Royal Marines and 29 Commando Regiment Royal Artillery, completing the 40-strong British training team.
"The Irish Defence Force is well versed in training and mentoring roles and it will be a privilege to command them," said Major Simon Holden, 1st Battalion The Royal Irish Regiment, Commanding Officer of the Infantry Training team.
"We have conducted several weeks of pre-deployment training together at Ternhill Barracks to prepare for the tour. It is an historic occasion.
"As the Officer in command of the Infantry Training Team I will be responsible for orchestrating the training of Malian troops working alongside the French, Czech and Danish forces, as part of the EU mission to bring stability to the region."
The training mission will take place in Koulikoro, north east of Bamako, and is expected to continue for around 15 months.
The MoD said it forms part of international efforts to support French troops in helping to stabilise the African nation against the threat of Islamist rebels.
Secretary of State for Defence, Philip Hammond MP, said: "Through this mission we will support the Malian government to counter the violent insurgency that has not only disrupted their country, but which also poses a clear threat to our national interests here in the UK.
"British support to the mission in Mali, including assistance with training, logistics and surveillance, highlights the impressive flexibility of our armed forces.
"British troops will not deploy in a combat role but, through training the Malian armed forces, we can assist in restoring order and denying terrorists a safe haven in the country."