Cremer, 39, returns after recovering from a left-arm injury that ruled him out following the 2026 T20 World Cup. He had previously spent seven years away from international cricket before making his comeback at the tournament in February.
Zimbabwe will begin their campaign against South Africa on August 29 before facing Namibia two days later. The three teams will meet twice in a double round-robin format, with the top two advancing to the final in Windhoek on September 6.
The squad comes without two key fast bowlers, with Test and ODI captain Richard Ngarava continuing his recovery from a lower-back injury. He will be monitored by Zimbabwe Cricket and is expected to return for the ODI series against Australia in September if fit.
Tanaka Chivanga is also unavailable after undergoing surgery for an Achilles tendon injury sustained during training. He will continue his rehabilitation under medical supervision.
Ngarava's absence means Raza will lead Zimbabwe in the T20I series, while Kundai Matigimu has been included after making one Test appearance for the country.
Brendan Taylor has also been left out of the T20I squad. He last played in the format against Oman at the World Cup and did not feature during Zimbabwe's T20I series against Bangladesh and India earlier this year, although he remains part of the Test setup.
Zimbabwe squad: Sikandar Raza (captain), Brian Bennett, Ryan Burl, Graeme Cremer, Ben Curran, Brad Evans, Innocent Kaia, Wessly Madhevere, Tadiwanashe Marumani, Wellington Masakadza, Kundai Matigimu, Blessing Muzarabani, Dion Myers, Newman Nyamhuri, Tafadzwa Tsiga.
Namibia have named a 16-man squad blending experience and youth for the inaugural T20I tri-series against South Africa and Zimbabwe in Windhoek from August 28 to September 6.
Pat Cummins has welcomed Australia's long-awaited return to South Africa, describing the Proteas as a "really strong side" as the visitors begin preparations for a three-Test series in October.
South Africa's preparations for the T20I tri-series in Namibia have suffered an early setback after all-rounder Jason Smith was ruled out with a right adductor muscle strain.
Proteas fast bowler Kagiso Rabada has suffered a hamstring injury while doing a winter training programme and will undergo further assessments with a home ODI series against Australia to come next month.
