How much do colleges in Ontario look at your eleventh grade marks?

some do and some dont.. if you are applying for early admission then they will every likely look at your grade 11 marks. if you apply along with everyone else and hav very good marks in grade 12 they will very likely only take the grade 12 marks into consideration. if your grade 12 marks are average they may or may not look at your grade 11 marks depending on what course you are applying to. good luck!