Cheap flights from St. Louis to Boston from $104

In general, November 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 November, then book flights to Boston from St. Louis during September instead. Flights to Boston in September, while not as cheap as those in November, still average around $447.

The cheapest day to depart from St. Louis to Boston is on a Saturday when prices can be found for as low as $544. 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 $641.

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 $526. 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 $853 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 $496 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.

You could potentially save up to 27% on your flight if you consider stops on a St. Louis to Boston flight.

As of October 2026, prices for St. Louis to Boston flights are approximately 55% more expensive when compared to flights at the same time last year.

Frontier is the most popular carrier operating from Lambert-St Louis to Boston Logan Intl

American Airlines, Southwest and Frontier are the top three most popular airlines that fly to Boston from St. Louis according to our data. American Airlines is the first choice among our users, with 48% of people opting to fly with this airline when traveling to Boston. Keep in mind that there are 5 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 October 2026. The most popular departure time for this route is 10:00AM, with 74% of flights per day taking off at noon.

As of October 2026, there are 38 flights per week flying from St. Louis to Boston. The most common day of the week flights depart is Sun, with 21% of flights taking off on this day.