| T.A.A. (Trans-Australia Airways) | Coastal Radio | Transmitting messages from T.A.A. aircraft. |
| Telegraph Construction and Maintenance Company. | Eastern Extension Cable laying Company | Contracted to lay the Pacific Cable in 1901. |
| Telegraph Operator - mail | New South Wales | Kiama (17 February 1864). |
| Tasmania | Green Ponds | |
| South Australia | ||
| Telegraph poles | Western Australia | The erection of a solitary pole at Geraldton. |
| Telegraph stamps | New South Wales | Set of 8 stamps issued in1871. |
| Western Australia | 1d bistre and 6d lilac. | |
| Australia (Interim period) | Red stamp with no denomination used on forms of Western Australia and Victoria. |
|
| Telegraphic Money Orders | New South Wales. | Establishment and transfer |
| Telephone | Tasmania | First call in the southern hemisphere - Campbelltown. |
| Theatre | Victoria | Letter sent by Dame Nellie Melba to Rt. Hon. Billy Hughes. |
| Time - Standard time and daylight saving. | All colonies | Adoption of standard time statutes. |
| Time - transmitting time signals. | Coastal Radio stations. | |
| Victoria | Time signal goven by ablack ball. | |
| Titanic | Coastal Radio | Changes to the distress call sent by ships, |
| Todd, Charles. | South Australia | Brief biographical summary. |
| Transit forms | Methods used to repeat a telegram from one station to another towards a destination. | |