Yes, but the button is not visible in all views. If you go to source view you should see the blame button at the upper right hand side of the code view pane. Depending on your version of bitbucket, it may be labeled as “annotate” instead of “blame” in an (unpopular with users) attempt to give the feature a more “positive” name!
https://bitbucket.org/site/master/issues/16318/blame-button-seems-to-be-missing