Yes but goldfish grow to 12" and at that size they'd kill the guppies. In fact, goldfish grow very, very quickly and the guppies wouldn't have long to live once the goldfish got to around 6". The same would apply to white cloud mountain minnows which are fine with young goldfish but can easily get killed by bigger fish. Peppered and bronze cories also work sometimes but you need slihtly warmer water.
You could try fathead minnows/rosy reds which are often sold as feeders if you live in the US and get to about 4". They are also very hardy (unlike modern fancy guppies) and are true coldwater fish.
You need to tell us how many gallons your tank is as well. The general rule is 20 gallons for one goldfish and 10 gallons for each additional goldfish. Also, goldfish like to be in groups. So if your new tank is at least 30 gallons and you only have 1, I'd get another and forget other tank-mates for the sake of your fish.
Also, do you do regular water changes? Do you de-chlorinate your water? (this is something a lot of goldfish owners manage to over-look)
