Law Abiding Citizen took second place in its opening weekend, with $21,039,502, behind Where the Wild Things Are. It went on to gross $126.6 million in total worldwide.

Law Abiding Citizen received generally negative reviews from critics. Review aggregator Rotten Tomatoes gave it a 26% score, based on 159 reviews with an average rating of 4.3/10. The website's critical consensus states that "Unnecessarily violent and unflinchingly absurd, Law Abiding Citizen is plagued by subpar acting and a story that defies reason." On Metacritic, the film has a weighted average score of 34 out of 100, based on 26 critics, indicating "generally unfavorable reviews".

In his review for the Chicago Sun Times, Roger Ebert said, "Law Abiding Citizen is the kind of movie you will like more at the time than in retrospect." He then went on to say, "Still, there's something to be said for a movie you like well enough at the time." Ebert rated the film 3 out of 4 stars.