Cannon Hill Park will host The 2015 Sousse and Bardo Memorial.
Thirty Britons were among 38 tourists killed by a gunman at Port El Kantaoui in an attack on 26 June. A UK tourist was one of 22 killed in a separate attack at a museum in Tunis in March.
The memorial is planned to open in 2018.
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The park was chosen following consultation with the victims' families.
It was selected due to its central location, as well as the balance between "seclusion and tranquillity" and "being a place of public prominence", the Foreign and Commonwealth Office (FCO) said.
FCO Minister for North Africa Tobias Ellwood said it will be a "place of remembrance for the families of those who lost their lives".
West Midlands victims include Charles Patrick Evans, 78, his son Adrian Evans, 49, and grandson Joel Richards, 19, who were killed in Sousse and Sally Adey, 57, of Shropshire, who died in the museum attack.
Councillor Lisa Trickett, cabinet member for environment at Birmingham City Council, said: "We are honoured that the families of the victims of this terrible massacre have chosen it as the place for their memorial.
"I hope that it will in some small way help the families directly affected, whilst also providing a space for everyone to remember, commemorate and reflect."
The Foreign Office is now inviting expressions of interest to design the memorial, which will be located on an oval-shaped site with views of the boating lake.
A shortlist will be announced at a later date.
A memorial dedicated to British tourists killed in two terrorist attacks in Tunisia in 2015 will be erected in a Birmingham park.