Harvard Square to Union Square, Somerville
The bus route from Harvard Square to Union Square, Somerville: where to board, where to change, where to get off and how late it runs.
Harvard Square to Union Square, Somerville
- Bus 109
- Take bus 109From Harvard, toward Linden Square via Sullivan6 stops, about 11 min
- Get off at Somerville Ave @ Union SqThe stop after Washington St opp Hawkins St
Weekdays, fall 2026 schedule · First and last trips
Quick answer: Take bus 109 to Somerville Ave @ Union Sq. The trip takes about 15 minutes (12-18 min depending on the connection). On weekdays bus 109 runs every 12 min during the day. Walking takes about 29 minutes, so on a nice day you may not need the T at all.
Get the live route from Harvard to Union Square
Step by step
- At Harvard, take bus 109 toward Linden Square via Sullivan.
- Ride 6 stops, about 11 min. Get off at Somerville Ave @ Union Sq, the stop after Washington St opp Hawkins St.
Other ways to go
- Take bus 69 to Cambridge St @ Prospect St, and walk about 12 min: about 20 min.
Which one is faster depends on when you leave. Cobblehop compares them with live times and gives you the one that gets you there first.
Times and frequency
| Day | First trip | Last trip | How often (daytime) | Trip time |
|---|---|---|---|---|
| Monday-Friday | 4:59 am | 1:07 am | Every 12 min | About 15 min |
| Saturday | 5:11 am | 1:22 am | About every 15 min | About 14 min |
| Sunday | 5:12 am | 1:00 am | About every 15 min | About 15 min |
First and last trip are when the first bus of the trip leaves Harvard, on the fall 2026 schedule. "How often" is for bus 109.
Late at night
On weekdays, the last trip that works leaves Harvard at 1:07 am and gets to Union Square, Somerville around 1:17 am. On Saturday nights the last trip leaves at 1:22 am, and on Sunday nights at 1:00 am. Late at night, ask Cobblehop for the last trip. It checks live times and tells you when to leave.
Tips for this trip
- Know your stop. Get to the door after Washington St opp Hawkins St. The next stop is Somerville Ave @ Union Sq. Start a live trip in Cobblehop and it alerts you before your stop.
- Union Square station is the end of the Green Line D branch, a short walk from the square.
Step-free access
MBTA data lists Harvard as accessible. Harvard has 2 elevators in MBTA data. Elevators do break, so check the MBTA's elevator alerts before you go.
What it costs
- Bus. $1.70 one way, like any local bus.
- How to pay. Tap a contactless credit or debit card, phone or watch at the fare gate or bus door, or use a CharlieCard or CharlieTicket.
- Kids. Children 11 and under ride the MBTA free.
Fares as of October 2026. Check the MBTA's fares page before you ride.
Harvard Square to Union Square, Somerville: common questions
How do I get from Harvard Square to Union Square, Somerville by public transit?
Take bus 109 to Somerville Ave @ Union Sq. The trip takes about 15 minutes (12-18 min depending on the connection).
How long does it take to get from Harvard Square to Union Square, Somerville?
About 15 minutes on the main route, or 12-18 minutes depending on the connection. Walking takes about 29 minutes.
Do I have to change buses?
No. Bus 109 goes all the way, so it's one ride.
How often does bus 109 run?
Every 12 min on weekdays during the day, about every 15 min on Saturdays and about every 15 min on Sundays, on the fall 2026 schedule.
What time is the last bus from Harvard Square to Union Square, Somerville?
On weekdays, the last trip that works leaves Harvard at 1:07 am and gets to Union Square, Somerville around 1:17 am. On Saturday nights the last trip leaves at 1:22 am, and on Sunday nights at 1:00 am.
Related routes
- Harvard Square to MIT Museum
- Harvard Square to MIT
- Kendall Square to Union Square, Somerville
- Back Bay Station to Union Square, Somerville
- Boston to Cambridge: Harvard and MIT (guide)
- Never miss your stop (guide)
More routes from Harvard Square
- Harvard Square to Assembly Row
- Harvard Square to CambridgeSide
- Harvard Square to Bunker Hill Community College
- Harvard Square to Museum of Science
- Harvard Square to Encore Boston Harbor
- All routes from Harvard Square
Official sources
Cobblehop is independent and isn't affiliated with these agencies or operators. Schedules on this page come from MBTA/MassDOT public data. Check their pages for the latest schedules and service changes:
Published October 30, 2026. Times were computed from the fall 2026 MBTA schedule (2026-11-04 for weekdays). Service changes, so check Cobblehop for live times before you go.
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