Rainier or Renier, son of William IV, Marquis of Montferrat, was the sixth ruler of the state of Montferrat in north-west Italy from about 1100 to his death, and the first such to be identified in contemporary documents as Margrave of Montferrat.
- Occupation
- ruler
- Position held
- marquis of Montferrat
- Born
- 1075
- Died
- 1137