Which Dragon's Den investor remained the show's longest-serving Dragon?

Peter Jones became Dragon's Den's longest-serving Dragon.

Jones was part of the original panel when the British programme began in 2005 and continued appearing after several other investors had departed. His tenure spans the show's major panel changes, making him the constant most closely associated with the investor line-up.

The original Dragons included Jones, Duncan Bannatyne, Rachel Elnaugh, Simon Woodroffe and Doug Richard. Deborah Meaden later became one of the programme's best-known investors, while Theo Paphitis and Bannatyne also had prominent runs, but neither matched Jones's continuous tenure.

“Longest-serving” concerns the investor's duration on the British series. It is different from questions about the presenter, the richest Dragon, or the investor who has made the largest individual deal. Those categories can produce different answers.