Tanzania now has a woman defence minister for the first time.
Stergomena Tax replaces Elias Kwandikwa, who died in August.
The president also revoked the appointment of three cabinet ministers and appointed a new attorney general.
Those sacked are the Communication Minister Faustine Ndugulile, Leonard Chamuriho (transport) and Medard Kalemani (energy).
President Suluhu brought back January Makamba whose appointment had been revoked by former President John Magufuli.
Mr Makamba will now head the energy ministry.
The president appointed Judge Eliezer Feleshi as the new attorney general to replace Adelardus Kilangi who has been appointed an ambassador.