A total of 35% of respondents wanted Sgt Alexander Blackman to serve no prison sentence, 23% believed he should do five years, 20% were in favour of 10 years, while 22% thought he should be imprisoned for more than 10 years.
The online poll of 900 people conducted by Survation found that, asked a more general question, 39% of voters said they disagreed with Blackman's 10-year minimum life sentence, while 37% were in favour.
Sir Gerald Howarth, a former defence minister and current MP for army garrison town Aldershot, said he agreed the sentence was too harsh.
'The highest standard of discipline must be maintained in the armed forces and this man obviously committed an offence," Sir Gerald said: "But 10 years is too much. Five years would be more appropriate."
Sir Gerald said that the court should have taken the marine's "fine record" following several tours of duty into account when handing down his sentence.
But arguing in favour of Blackman's punishment, former Lib Dem leader and ex-Royal Marine Lord Ashdown said he was content with the judge's decision to follow the law.
Defence Secretary Philip Hammond said he recognised the "huge amount of public interest" in the case but declined to pass comment himself on the sentence.