Peter Jones is the only original UK Dragon's Den investor to have stayed on the panel throughout the series.
Jones joined the programme when the British version began in 2005. The original panel also included Duncan Bannatyne, Rachel Elnaugh, Theo Paphitis and Doug Richard, but the composition changed as investors departed and new dragons arrived.
His continuing presence made Jones the programme's longest-serving original dragon. He is a British entrepreneur and investor whose business interests have included mobile communications, technology and leisure ventures. On the programme, he is known for examining valuation, ownership percentages and the scalability of a pitch.
This fact is different from asking which dragon was the longest-serving investor overall or which investor left the programme first. It specifically concerns continuity from the original 2005 panel. Several other prominent dragons appeared for many series, but they did not remain from the launch panel through the entire run.