James Cromwell is not directly descended from Oliver Cromwell. Although they share the same surname, there is no established genealogical connection between the two.
Oliver Cromwell, who lived in the 17th century, was a prominent English military and political leader best known for his role in the English Civil War and as Lord Protector of the Commonwealth of England. He was a significant figure in English history, whereas James Cromwell, born in 1940, is a contemporary actor known for his roles in film and television.
The similarities in their last name can lead to some assumptions, but many people have the same surname without being related. In this case, James has not presented evidence to suggest that he has any ancestral ties to Oliver Cromwell.