The 2006–07 National Division One was the 20th full season of rugby union within the second tier of the English league system, currently known as the RFU Championship.
This season saw the league increased from 14 to 16 teams with new teams including Leeds Tykes (relegated from the 2005-06 Guinness Premiership), as well as Moseley and Waterloo who were promoted from 2005–06 National Division Two.