When can I expect my baby to sleep through the night?

3-6 months. By age 3 months babies have start a more regular sleep/wake pattern and have dropped most of their night feedings. Somewhere between 3-6 months, most babies can sleep through the night for 5-6 hours.
4-6 months. All babies should sleep at least 8 hours without eating by 6 months of age. Some can do it at 4 months, some earlier, but at 6 months I would stop feeding them at night and they will learn to not wake up for food since their bodies can go 8 hours.