Theodor Fahrner (4 August 1859 – 22 July 1919) was a German jewelry designer and trained steel engraver from Pforzheim, known for his Art Nouveau and Jugendstil creations. His pieces were celebrated for their artistic quality while remaining affordable. After his death, his company became a leading name in Art Deco jewelry design.

Theodor Fahrner was born to Theodor Fahrner Sr. and Pauline Fahrner (née Schweikert). He had six sisters: Emma, Julie, Lina, Paulina Emilie, Luise Emilie, and Bertha. Little is documented about his early education, but he trained as a steel engraver and studied at the Pforzheim Kunstgewerbeschule.

His father owned a ring manufacturing business, which Fahrner inherited upon his father’s passing in 1883. By 1895, he had taken full control of the company. During the artistic and industrial shifts of the late 19th century, he registered multiple patents and utility models. His breakthrough came in 1900 when he showcased jewelry designed by Max J. Gradl at the Paris World Exposition, earning a silver medal.

From 1899 to 1906, Fahrner personally designed much of the company’s jewelry. Later, notable designers such as Maria Obrich, Patriz Huber, and Ludwig Knupper contributed to the brand’s evolving style. Under his leadership, the firm became renowned for its accessible yet stylish Art Deco jewelry, gaining an international reputation.

Fahrner passed away in Pforzheim on July 22, 1919, leaving behind two daughters, Vera and Yella. He was buried in Pforzheim’s main cemetery. Following his death, jeweler Gustav Braendle of Esslingen acquired the company, continuing production under the name Bijouteriewarenfabrik Gustav Braendle. The brand name "Fahrnerschmuck" remained in use, preserving Fahrner’s legacy in the jewelry industry.