Based on internal knowledge of the production and cast of *Star Wars: The Last Jedi* (2017), the oldest principal cast member at the time of filming was **Frank Oz**.
### Specific Details:
* **Cast Member:** Frank Oz (born Richard Frank Oznowicz).
* **Role:** He returned to play the iconic character **Yoda**.
* **Age at Time of Filming:** Frank Oz was born on May 25, 1944. Principal photography for *The Last Jedi* took place primarily between **February 2016 and July 2016**. Therefore, Oz was **71 years old** when filming began and turned **72 years old** during the production.
* **Detailed Context of the Role:** While Yoda appeared in the prequel trilogy primarily as a CGI character (and a voice-only cameo in *The Force Awakens*), director Rian Johnson wanted the character to appear as a "Force Ghost" in *The Last Jedi* using the physical aesthetic of the original trilogy. Frank Oz did not just provide the **voice**; he also returned to his roots as a **puppeteer**. He physically operated the Yoda puppet on set, working with a team of assistants to match the movements and "feel" of the puppet used in *The Empire Strikes Back*.
**Other notable veteran cast members for comparison:**
* **Andrew Jack** (General Ematt) was also born in 1944 (January), making him slightly older than Oz, but he was a supporting character/dialect coach.
* **Peter Mayhew** (Chewbacca) was born in May 1944 (six days before Oz), but due to health issues, he served primarily as a "Chewbacca Consultant" on *The Last Jedi*, while Joonas Suotamo took over the physical performance.
* **Anthony Daniels** (C-3PO) was 70 years old during filming (born 1946).
* **Mark Hamill** (Luke Skywalker) was 64–65 years old during filming (born 1951).
* **Carrie Fisher** (General Leia Organa) was 59–60 years old during filming (born 1956).