Joseph Mwengi Mutua (born 10 December 1978 in Machakos, Eastern Province) is a Kenyan runner who specializes in the 800 metres.

His personal best time is 1:43.33 minutes, achieved in August 2002 in Zürich. He holds the African indoor record in 800 m with 1:44.71 minutes, achieved in January 2004 in Stuttgart.^[1]

He twice competed at the Summer Olympics. In 2000, he failed to advance 800 metres heats, but was part of the Kenyan 4*400m relay team that reached semifinals. At the 2004 Summer Olympics, he reached 800 metres semifinals.^[2]

He won the Kenyan national championships in 2002, 2003 and 2004.

He was part of the 4 × 800 m relay team who currently holds the world record.