Christopher Jones was the "Master of the Ship" when the Mayflower sailed for America in 1620. The title of "Captain" was not used. Jones also was a partial (1/4) owner of the vessel. There were 102 passengers and approximately 30 crew members.

John Clark (Clarke) was Masters Mate and Pilot. In 1620, Clark already had seen several adventures. His piloting career began in England about 1609. In early 1611 he was pilot of a 300-ton ship on his first New World voyage with a three-ship convoy sailing from London to the new settlement of Jamestown in Virginia.

Myles Standish was a "Captain" selected by the Pilgrims as their military officer. Standish played a leading role in the administration and defense of Plymouth Colony from its inception.

William Bradford was a Separatist religious leader who sailed on the 'Mayflower' and eventually became governor of the Plymouth settlement.

More Info: en.wikipedia.org