The Thirty Meter Telescope (TMT) Project will design and build a thirty-meter diameter telescope for research in astronomy at optical and infrared wavelengths. TMT is a partnership between the University of California, Caltech, Association of Canadian Universities for Research in Astronomy (ACURA), and the Association of Universities for Research in Astronomy (AURA). The TMT design and development phase is funded and work is underway. We include a high level description of the design of the telescope and its planned adaptive optics and science instrumentation. The organizational structure of the project is summarized along with the schedule of key milestones in the design. We are carrying out key conceptual and cost reviews in 2006 and will be prepared to begin construction in 2009, with first light in 2015.© (2006) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.