| T | functional programming, imperative programming, multi-paradigm programming, metaprogramming, object-oriented programming | 1982 | Stephen Slade |
| T++ | — | 1980 | — |
| TACL | — | — | Tandem Computers |
| TACPOL | structured programming | — | — |
| TADS | prototype-based programming | 1988 | — |
| Tcl | multi-paradigm programming, procedural programming, event-driven programming, functional programming, imperative programming, object-oriented programming | 1988 | John Ousterhout |
| TclX | — | — | Mark Diekhans, Karl Lehenbauer |
| Tea | object-oriented programming, functional programming, multi-paradigm programming | 1997 | — |
| TECO | — | 1962 | Daniel Murphy |
| Tekkie Uni | — | — | — |
| TELCOMP | — | 1965 | BBN Technologies |
| Teml | — | — | Borland |
| TeX | — | 1978 | Donald Knuth |
| Text Executive Programming Language | — | 1979 | — |
| The join calculus language | — | — | — |
| THINK C | — | — | Gen Digital |
| Thue | — | 2000 | John Colagioia |
| TI BASIC | — | 1979 | Texas Instruments |
| TI-BASIC | — | — | Texas Instruments |
| TI-BASIC 83 | procedural programming | — | — |
| Timber | — | — | — |
| Tink | esoteric programming | 2008 | — |
| Tiny BASIC | — | 1975 | — |
| TinyScheme | — | 1998 | — |
| TLA+ | action language | 1999 | — |
| TMG | — | 1963 | — |
| Toit | — | — | — |
| Tom | — | 2001 | — |
| TOM | object-oriented programming | 1999 | — |
| TOMVIEW | — | — | — |
| ToonTalk | concurrent constraint logic programming | 1995 | — |
| Topology and Orchestration Specification for Cloud Applications | — | — | OASIS |
| TouchDesigner | — | — | — |
| TouchDevelop | — | 2011 | — |
| TRAC | — | 1964 | Calvin Mooers |
| Trade Space Visualizer | — | — | — |
| Transact-SQL | procedural programming | — | — |
| TREE-META | — | 1968 | — |
| Treetop | — | 2006 | — |
| Trellis-Owl | — | — | Digital Equipment Corporation |
| Tritium | — | — | — |
| Triton | — | — | OpenAI |
| Triton (programming language) | — | — | — |
| True BASIC | — | 1983 | — |
| TTCN | — | 1992 | — |
| TTCN-3 | — | — | — |
| TTM | — | 1968 | — |
| Turbo Basic | — | 1987 | Borland |
| Turbo C++ | — | 1990 | Borland |
| Turbo Pascal | object-oriented programming | 1983 | Borland, Anders Hejlsberg |
| Turbo Pascal OOP | — | 1989 | — |
| Turbo-BASIC XL | — | — | Frank Ostrowski |
| Turbo51 | object-oriented programming | — | — |
| TurboWarp | — | — | — |
| Turing | procedural programming, object-oriented programming | 1982 | Holt Software Associates |
| Turtlestitch | — | — | — |
| TUTOR | procedural programming, imperative programming | 1969 | — |
| TXL | functional programming | — | James Cordy |
| TypeScript | generic programming, event-driven programming, functional programming, imperative programming, object-oriented programming | 2012 | Microsoft |