No committee previously had been able to send similar legislation this far, The Providence Journal reported Tuesday.
The state's marriage code now reads, "Marriage is the legally recognized union of two people."
The newspaper said state Rep. Arthur Handy's bill may be voted on by the full House as early as Thursday.
Supporters of the bill crowded into the committee room prior to Tuesday's vote, the newspaper said.
N.J. man wakes up from 10-hour sleep with knife in back
Wisconsin business offering 'therapeutic cuddling' forced to close