Connecticut is the third most Catholic state in America, ranking just behind Rhode Island and New Jersey, in a national analysis by the Gallup organization. Twenty-three percent of all Americans identify as Catholics, but there is wide variation in Catholic representation across states -- ranging from 44 percent in Rhode Island, the most Catholic state in the nation, to 6 percent in Alabama. Connecticut is at 38 percent. Other states with above-average Catholic representation include New York and New Hampshire, and then several more geographically dispersed states including New Mexico, Illinois, California and Wisconsin. One of the most significant trends in American religion in recent years, according to Gallup, has been the increase in the percentage of Americans who have no formal religious identity, rising from 15% in 2008 to 21% in 2017. These so-called "nones" are most prevalent in the two most Western states of the U.S., Hawaii and Alaska, and also constitute relatively high proportions of the population in a number of other Western and New England states: Washington, Vermont, Oregon, Maine, Colorado, New Hampshire and California.
Overall, the Gallup analysis found that Americans continue to be geographically segregated by religion. Protestants dominate in the South, while Catholics are most common in the Northeast and mid-Atlantic, with some representation in the Midwest. Two smaller religious groups are also geographically concentrated: Mormons are a major population factor in Utah and Idaho, and Jews tend to be disproportionately located on the East Coast, the review of religion in America found.
About half of Americans (48%) identify as Protestants or other Christians who are not Catholic or Mormon. Protestants have long been a fixture of the Southern Bible Belt and that trend continued in 2017.
Connecticut has the fourth largest Jewish population, at four percent. Only New York (8%), New Jersey (6%) and Massachusetts (5%) have larger Jewish populations. Nationwide, Americans who identify their religion as Jewish are a small percentage of the U.S. adult population -- about 2% according to Gallup's review of 2017 data.
In a similar survey in 2004, Gallup ranked Connecticut as having the fourth highest Catholic population, at 46 percent, behind Rhode Island, Massachusetts and New Jersey. At that time, the state's Jewish population was the sixth highest percentage among the states, at three percent.