This paper presents a new symbolic corpus of musical themes from the complete Star Wars trilogies (Episodes I-IX) by John Williams. The corpus files are made available in multiple formats (.krn, .sib, and .musicxml) and include melodic, harmonic, and formal information. The Star Wars Thematic Corpus (SWTC) contains a total of 64 distinctive, recurring, and symbolically meaningful themes and motifs, commonly referred to as leitmotifs. Through this corpus we also introduce a new humdrum standard for non-functional harmony encodings, **harte, based on Harte (2005, 2010). This report details the motivation, describes the transcription and encoding processes, and provides some brief summary statistics. While relatively small in scale, the SWTC represents a unified collection from one of the most prolific and influential composers of the 20th century, and the under-studied subset of film and multimedia musical material in general. We hope the SWTC will provide insights into John Williams' compositional style, as well as prove useful in comparisons against other thematic corpora from film and beyond.