Chiba Toshitane served as a sengoku daimyō during the Sengoku period. He was the twenty-fifth head of the Chiba clan of Shimōsa Province.
Toshitane was born as the eldest son of Chiba Masatane, the twenty-fourth head of the Chiba clan.
During this youth, attacks by the Oyumi kubō and Satomi clan caused the loss of authority even the main base of the Chiba clan at Inohana. Despite customary practices for the clan, a coming-of-age ceremony could not be held at the Chiba-Myōken Shrine. On 11/15 of Daiei 3 (1523), the ceremony was conducted at the Sakura-Myōken Shrine near the main base at Sakura and a messenger sent to the Chiba-Myōken shrine to report the holding of the event.
In 1546, following the demise of his father, Toshitane succeeded him. Within the Chiba clan, senior retainers including Hara Tanekiyo were influential voices. Around this time, he was engaged in a dispute with his younger brother, Usui Tanehisa. At the Siege of Kawagoe Castle, he was the only head of a clan in the Kantō to serve on the side of the Hōjō but died just one year after inheriting the headship of the clan so there are few traces of his activities. He was thirty-three years old.
Toshitane was succeeded by his son, Chiba Chikatane. (Under another theory, he did not have a natural son so had his youngest brother, Chikatane, succeed him.)
At the Kairin Temple in the city of Sakura in Chiba Prefecture, there is included among a group of stone pagodas from the Middle Ages a pagoda with a memorial inscription for Toshitane as well as his father, Masatane, and other members of the family.