| Top-Platzierung | Baden-Württemberg |
| Top-Print Electronic GmbH | Bavaria |
| top.media GmbH | |
| TOP500 Supercomputers | Baden-Württemberg |
| Topas Therapeutics GmbH | |
| Topcom Kommunikationssysteme GmbH | North Rhine-Westphalia |
| Topi GmbH | |
| TopM Software GmbH | Bavaria |
| TOPO graphics Geoinformationssysteme GmbH | North Rhine-Westphalia |
| Topobyte | |
| Topopt GmbH & Co. KG | Bavaria |
| TOPOS Personalberatung GmbH | |
| tops.net GmbH & Co. KG | Hesse |
| TOPTICA Photonics AG | Bavaria |
| TopWare Interactve | Baden-Württemberg |
| Torben Bues Consulting & Services IT GmbH | |
| Torro-Softworks GmbH | Brandenburg |
| TOSHIBA Europe GmbH | North Rhine-Westphalia |
| Touch Art | Schleswig-Holstein |
| Tourbosoft GmbH | |
| Tower Electronic Components GmbH | Baden-Württemberg |
| Tozero GmbH | |
| tp-net OHG | North Rhine-Westphalia |
| TPS Data GmbH | Baden-Württemberg |
| TQ-Systems GmbH | Bavaria |
| TR Electronic GmbH | |
| Traceless Materials GmbH | |
| TraceTronic GmbH | |
| Tracon Wismar Tradin & Consulting GmbH | Hesse |
| Trade Republic Bank GmbH | Berlin |
| TRADE Software-Systeme GmbH | Baden-Württemberg |
| Tradegate AG | |
| TradersWorld GmbH | Baden-Württemberg |
| Tradewind | |
| Trading Company KG | Hesse |
| tradingtwins GmbH | |
| Tradum GmbH | |
| Traffic Data Systems GmbH | |
| traffics Softwaresysteme für den Tourismus GmbH | Berlin |
| Traffitec GmbH | North Rhine-Westphalia |
| Traffix GmbH | Bavaria |
| Trafo2 GmbH | North Rhine-Westphalia |
| Tragant Handels- und Beteiligungs GmbH | Berlin |
| Train & Education | Berlin |
| Trajet GmbH | Lower Saxony |
| Trans-Logo-Tech (TLT) GmbH | |
| Transdata | North Rhine-Westphalia |
| Transfact GmbH | North Rhine-Westphalia |
| Transimmune AG | |
| Transinsight GmbH | Saxony |