He joined Sussex in 1986, playing two Youth Test matches the following calendar year, against Sri Lanka Young Cricketers. In July 1987, he participated in his debut Second XI Championship match, in a draw against Hampshire. Participating in the competition six more times over the next six years, he didn't appear again in the Second XI side until 2000, instead participating in the senior First XI with great frequency. He first played in the 1987 B&H Cup, continuing in that competition for five years, before playing in it for the last time in 1996.
He finished his career in 2003 for Northumberland, making his bow in the 2003 C&G Trophy. In 1992 Speight won the Walter Lawrence Trophy for the fastest first-class century. Following his retirement, he coached South Northumberland CC, moving between several schools as a cricket coach.
He is currently head of hockey and cricket at Sedbergh School, a private boarding school in Cumbria. He hosts an annual 'Martin Speight Cricket academy', during the summer. He is also a commentator for BBC radio Newcastle for selected Durham fixtures.
