var universe = from oa in context.vOfficeAddresses where oa.StateProvince == "Ontario" select oa;

var query = from oa in universe 
			select new { 
				oa, 
				contact = (from c in context.Contacts where c.ContactID == oa.ContactID select c) 
			};
var AddressesWithContacts = query.ToList();

var universe = from oa in context.vOfficeAddresses where oa.StateProvince == "Ontario" select oa;

var query = from oa in universe
select new
{
oa,
contact = (from c in context.Contacts where c.ContactID == oa.ContactID select c)
};
var AddressesWithContacts = query.ToList();

Note: An order operator in a subquery will be ignored. The main query controls ordering.

Break nested query out of main query in LINQ

C#