The only people who can sponsor you in most provinces are your parents if you are under age or your children if they are Canadian citizens and 18 or older and making enough money or your spouse / common law partner. Siblings, aunts and uncles (siblings of your parents) could also sponsor you if you are under 18 and an orphan.
There is a clause stating that a person can sponsor "one other relative" but this is only if that person has no family or spouse in Canada and no other closer relatives alive that they could sponsor.
Then you have the provincial nominee programs in Manitoba and Saskatchewan and they allow a few more options.
You can find the MB PNP here:
http://www2.immigratemanitoba.com/browse/howtoimmigrate/pnp/pnp-family_support.html and SINP here:
http://www.saskimmigrationcanada.ca/family-members where it says that if you have first degree cousins there, those are the children of your parents siblings, they can sponsor you. Manitoba also offers that if you have 2 distant relatives there who will sponsor you, that will also work, see
http://www2.immigratemanitoba.com/browse/howtoimmigrate/pnp/pnp-general.htmlFor these programs, you need to meet certain requirements for age, funds, education and work experience and your relatives must have lived in the province for at least one year.