Cheap flights from St. Louis to Boston from $109

In general, December is the cheapest month to fly from St. Louis to Boston. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $444. If you aren’t able to travel during the month of December, then book flights to Boston from St. Louis during November instead. Flights to Boston in November, while not as cheap as those in December, still average around $444.

The cheapest day to depart from St. Louis to Boston is on a Thursday when prices can be found for as low as $553. Be sure to avoid booking your departure on a Monday as prices are generally higher than usual. According to our data, the average ticket price to Boston on Monday is $639.

According to our data, the cheapest time of day to fly to Boston is in the evening. momondo users have found flights departing from St. Louis to Boston in the evening for as low as $522. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. At noon is when there is more demand to fly to Boston, so prices are often more expensive at around $924 per ticket.

Fly from Lambert-St Louis to Boston Logan Intl for the best Lambert-St Louis - Boston Logan Intl flight prices

You are more likely to see cheaper flights to Boston from St. Louis when booking weeks ahead of your departure date. In general, you can expect to find flights to Boston for around $494 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Boston from St. Louis for as low as $420 on momondo.

There are 4 cabin classes available to choose from on St. Louis to Boston flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

United Airlines, Southwest, and Delta are the most popular carriers operating from Lambert-St Louis to Boston Logan Intl

Southwest, American Airlines and Frontier are the top three most popular airlines that fly to Boston from St. Louis according to our data. Southwest is the first choice among our users, with 49% of people opting to fly with this airline when traveling to Boston. Keep in mind that there are 6 different airlines that fly to Boston on a routine basis, so you have a few additional options to choose from.

Atlanta (ATL) was the most common stop: 75% of momondo users choosing 1-stop flights on this route connected there.

Flights via Philadelphia (PHL) offer the lowest average round-trip price of $450.

Flights connecting via Philadelphia (PHL) have the shortest average one-way travel time: 5h 18m.

Philadelphia (PHL) has the shortest average layover time for this route: 1h 18m.

5 flights are operational daily from St. Louis to Boston as of November 2026. The most popular departure time for this route is 9:00AM, with 69% of flights per day taking off at noon.

As of November 2026, there are 40 flights per week flying from St. Louis to Boston. The most common day of the week flights depart is Mon, with 20% of flights taking off on this day.