The Sienna earns straight As in the second row, and its third row grades nearly as well. The van Cars.com tested had captain's chairs and does not fit three across, though Cars.com notes it has previously tested a Sienna with a second-row bench seat. A 5-foot-6-inch front passenger had tons of legroom with a rear-facing seat behind them.
Compiled by our gear team from Cars.com's Car Seat Check. Published July 18, 2026. Car seat fit findings from Cars.com's Car Seat Check, conducted by certified child passenger safety technicians. Cars.com performed this check on a 2021 Toyota Sienna, so confirm the second-row layout on the model year you are buying.
The grades at a glance
| Test | Grade |
|---|---|
| LATCH | A |
| Infant seat | A |
| Rear-facing convertible | A |
| Forward-facing convertible | A |
| Booster, second row | A |
| LATCH, third row | A |
| Forward-facing convertible, third row | A |
| Booster, third row | B |
| Third-row entry | B |
Three car seats across: no, in the second-row captain's chairs Cars.com tested. The van Cars.com tested had second-row captain's chairs, so there was no middle seat. A second-row bench is offered on some builds, but Cars.com did not test one for this model year, so confirm the configuration on the specific vehicle. Cars.com did not test a bench-seat version, so treat this as a finding about that configuration rather than about the model.
Where the anchors are
Lower anchors. Second row: two sets, exposed for easy access. Third row: two sets in the outboard positions, also exposed.
Top tethers. Two halfway down the second-row seatback, clearly marked. Three atop the third-row seatback, also clearly marked.
NHTSA recommends always using the top tether with a forward-facing car seat, whether it is installed with the lower anchors or the seat belt, as long as both the car seat manufacturer and the vehicle manufacturer permit it. Check both manuals for your specific combination, and check your car seat's tether weight limit: NHTSA directs you to stop using the tether once your child exceeds it, even while they still fit the seat. Our car seat safety guide covers how to use it.
Infant car seats
Went in easily on Toyota's extra-long-slide chairs, and the 5-foot-6-inch front passenger had tons of legroom with the seat installed behind them.
That matters more than it sounds. In a lot of compact vehicles a rear-facing seat pushes the front passenger forward until the front row is unusable. Browse the infant car seats we carry, and if you are weighing whether a rotating base is worth it, see our comparison of rotating versus standard infant seats.
Convertible car seats
Rear-facing. Same story: easy install, ample front passenger legroom.
Forward-facing. An A in both the second and third rows.
Some vehicles need the head restraint removed or raised to seat a car seat flush against the seatback, and some have fixed restraints that cannot be moved at all. Check your vehicle manual before forcing anything, and note that where a fixed restraint holds the seat off the seatback, that is a fit problem rather than something you can work around. See our convertible seats.
Boosters
Second row is an A, with stable buckles kids should manage alone. The third row drops to a B: the head restraint flops down but does not come out, and only the passenger-side buckle is stable, with the other two sitting flush with the cushion.
Getting to the third row
The second-row seats can be cumbersome to move, but they collapse with a bit of muscle and open a wide passage. Cars.com notes that collapsing them will not work with a car seat installed, which is the situation most families reading this are actually in.
Will your stroller fit?
Cars.com's Car Seat Check does not measure cargo volume, so the stroller guidance below is ours rather than theirs. Note that a minivan floor is about the friendliest surface there is for a folded stroller.
Cubic feet is the wrong number to shop on anyway. What decides whether a stroller fits is its folded footprint against the width between your wheel wells and the height to your cargo cover. A trunk can have generous volume and still refuse a wide fold.
Measure the space you will actually load into, whatever shape it is: how deep it is, its narrowest width (usually between the wheel arches, or between the bed rails on a pickup), and the height of the opening you have to lift over. Then compare against the folded dimensions of whatever you are considering. If the numbers are close, a compact fold like the Cybex Beezy leaves room for everything else; if you have space to spare, a full-size frame like the UPPAbaby Vista V3 earns it back in storage and expandability. Browse all strollers.
Toyota Sienna takeaway
This is what a vehicle designed around car seats looks like. The second row's long slide is the real advantage, because it buys front passenger legroom even with a rear-facing seat behind it.
Across every vehicle: Which cars fit three car seats · Which cars let kids buckle themselves
More car seat help: Car Seat Safety Guide · All buying guides
Educational information only. This guide is for general education. It is not professional, medical, legal, or safety advice, and it does not create any advisory or professional relationship between you and SugarBabies. You are responsible for the safe selection, installation, and use of any car seat.
How a car seat fits and installs depends on your exact vehicle (its model year, trim, and seating configuration) and your exact car seat model. The instructions that came with your car seat and your vehicle owner’s manual always control. If anything in this article ever conflicts with those instructions, or with current guidance from the National Highway Traffic Safety Administration (NHTSA), follow the manufacturer instructions, your vehicle manual, and NHTSA, not this article.
Our fit findings are compiled from third-party sources, including independent car seat fit testing performed by Certified Child Passenger Safety Technicians and manufacturer specifications, that we believe to be reliable, and we provide all of it “as is.” Specifications, model years, and vehicle configurations change, and we do not guarantee the accuracy, completeness, or current status of any of it. This article does not replace a hands-on check by a Certified Child Passenger Safety Technician (CPST). If you are near Sumner, Washington, our in-store CPST check is free with every infant seat we sell, and we encourage you to use it or to find a certified technician near you.
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