The oboe d'amore, the alto member of the oboe family, enjoyed its most popular period between the years 172 and 176. While no date for the invention of the instrument has been established, the first known composition to use the oboe d'amore can be dated from as early as 1717. Composition for the instrument was restricted to composers living in the area bounded approximately by Hamburg, Munster, Vienna, and Berlin. The earliest known works which use the instrument are sacred vocal works and reflect an association with alto and tenor voices and texts dealing with love. Gradually, the instrument filtered through every aspect of early eighteenth-century musical society and works which utilized the oboe d'amore include cantatas, passions, operas, solo concerti, concerti grossi, orchestra suites, and chamber works. Georg Philipp Telemann (1681-1767), one of the most prolific and respected composers of his time, wrote extensively for the oboe d'amore -- at least twenty-two works which use the instrument can be attributed to Telemann. One of the first to write for the instrument, Telemann, unlike his contemporaries, composed in every medium available. Through an examination of Telemann's works for oboe d'amore, which comprise a central part of the instrument’s repertoire, it is possible to observe the development of composition for oboe d'amore, the dissemination of the instrument through musical society, and the style of writing which brought the instrument to the peak of its popularity. The writing is particularly instructive in regard to utilization of the instrument's color, range, and technical ability. In addition, consideration of the instrument helps shape the form of each work. Relatively few of Telemann’s works which use oboe d'amore are available in published editions. As a result, an overview of Telemann's writing for the instrument has been unavailable. Previous research regarding the oboe d'amore has centered in the sacred cantatas of J.S. Bach and in compiling repertoire lists, leaving an inaccurate impression of the general style and methods of writing for the instrument. The critical editions of four works provided in this thesis represent the various genres in which Telemann wrote for the oboe d'amore. In addition, each work displays Telemann's technical and aesthetic handling of the instrument. The analysis of these works, and description of the rest of Telemann's writing for the oboe d'amore provides a better understanding of the instrument in the context of the period of use from its invention to its virtual demise, an exploration of some of Telemann's best and most conscientious writing, and an insight into performance practice.