Catholic voters went for Barack Obama by 50 to 48 percent, mirroring the national result according to exit polls.
Catholics have voted for the winner in every election since 1972, making them one of the most reliable swing vote barometers.
Many Catholics are Hispanic and there is no breakdown of the numbers between how Hispanic Catholics and other Catholics voted.
Catholics still voted for the incumbent despite efforts by many Catholic bishops to portray parts of Obamacare which deal with contraception as an attack on religion.
In addition, three states passed same sex marriage laws despite strong opposition from Catholic leaders. Voters in Washington, Maine and Maryland supported the marriage legislation.
Maine Catholic Bishop Richard Malone said he was "deeply disappointed" that Maine voted for gay marriage.
Malone said Catholics who support same-sex marriage are "unfaithful to Catholic doctrine."
Baltimore Archbishop William Lori had a letter read from the altar defending traditional marriage.
In addition, several bishops denounced abortion pro-choice candidates, all Democrats, from the altar and urged their flocks not to support them.
Minnesota rejected a ballot measure to make marriage legal only between a man and a woman.