In February 2013, Cromwell was arrested along with animal rights activist Jeremy Beckham for interrupting a University of Wisconsin Board of Regents meeting while showing a graphic photo of a cat to protest about alleged mistreatment of animals on campus.
 The incident, which garnered widespread press coverage, was resolved on March 25, 2013, when an attorney representing Cromwell entered no-contest pleas to the non-criminal offense and agreed to pay $100 forfeitures and court costs of $263.50.
In December 2015, he was removed from an event in New York for heckling an energy company receiving an award.

On December 18, 2015, Cromwell and five other people were arrested while protesting against the construction of a natural gas power station in Wawayanda, New York, near his home in Warwick, New York.
He and his fellow protesters, called the "Wawayanda Six" were convicted of disorderly conduct and obstruction of traffic.
They were fined $375, due June 29, 2017 and sentenced to 16 hours of community service.
After refusing to pay the fine, he was sentenced to a week in jail, scheduled to go on July 14.
However, they were released 3 days later on July 17.
Cromwell and fellow Star Trek actor J. G. Hertzler were among the 19 people arrested in Watkins Glen, New York on June 6, 2016, for a protest against underground gas storage in salt caverns near Seneca Lake.
On June 6, 2017, he was escorted out of a Democratic Party fundraiser (which  New York Governor Andrew Cuomo and House Minority leader Nancy Pelosi attended) after disrupting the event by protesting about the power station.
Cromwell was again arrested, this time for trespassing after taking part in a protest along with PETA at Seaworld on July 24.

On October 31, 2019, Cromwell was again arrested with 34-year-old animal rights activist Jeremy Beckham.
They were charged with disorderly conduct after police said they disrupted a meeting of the Texas A&M University System Board of Regents.
The two were part of a demonstration by People for the Ethical Treatment of Animals to protest A&M's use of dogs for medical research.
Both were released after posting bonds of $5,000 each.
In February 2013, Cromwell was arrested along with animal rights activist Jeremy Beckham for interrupting a University of Wisconsin Board of Regents meeting while showing a graphic photo of a cat to protest about alleged mistreatment of animals on campus.  The incident, which garnered widespread press coverage, was resolved on March 25, 2013, when an attorney representing Cromwell entered no-contest pleas to the non-criminal offense and agreed to pay $100 forfeitures and court costs of $263.50. In December 2015, he was removed from an event in New York for heckling an energy company receiving an award.
On December 18, 2015, Cromwell and five other people were arrested while protesting against the construction of a natural gas power station in Wawayanda, New York, near his home in Warwick, New York. He and his fellow protesters, called the "Wawayanda Six" were convicted of disorderly conduct and obstruction of traffic. They were fined $375, due June 29, 2017 and sentenced to 16 hours of community service. After refusing to pay the fine, he was sentenced to a week in jail, scheduled to go on July 14. However, they were released 3 days later on July 17. Cromwell and fellow Star Trek actor J. G. Hertzler were among the 19 people arrested in Watkins Glen, New York on June 6, 2016, for a protest against underground gas storage in salt caverns near Seneca Lake. On June 6, 2017, he was escorted out of a Democratic Party fundraiser (which  New York Governor Andrew Cuomo and House Minority leader Nancy Pelosi attended) after disrupting the event by protesting about the power station. Cromwell was again arrested, this time for trespassing after taking part in a protest along with PETA at Seaworld on July 24.
On October 31, 2019, Cromwell was again arrested with 34-year-old animal rights activist Jeremy Beckham. They were charged with disorderly conduct after police said they disrupted a meeting of the Texas A&M University System Board of Regents. The two were part of a demonstration by People for the Ethical Treatment of Animals to protest A&M's use of dogs for medical research. Both were released after posting bonds of $5,000 each.
James Cromwell