399 Marion Avenue

Set among towering redwoods on a quiet Mill Valley street, this one-of-a-kind home offers something rare: the feeling of living in a private forest retreat while staying moments from town, schools, parks, and daily conveniences. Thoughtfully designed with Zen-inspired outdoor spaces, two expansive decks, and treetop views from nearly every room, the home invites a slower, more connected way of living- morning coffee in the trees, family dinners under the canopy, and weekends filled with fresh air and adventure. A welcoming front deck leads into the main living level, where the living, dining, and kitchen spaces flow in an open-concept layout filled with natural light from oversized windows and skylights. The chef's kitchen features granite countertops, custom wood cabinetry, premium stainless appliances, and a generous island for gathering, homework, and casual meals. Rear deck access makes indoor-outdoor entertaining effortless. Downstairs, the private primary suite feels like a true sanctuary, opening to its own secluded deck. The newly renovated spa-style bath includes a deep porcelain soaking tub, heated shower floors, multiple shower heads, custom teak detailing, and a gray water diverter system that can nourish the surrounding redwoods. An additional bedrooms and a full bath complete this level, including a spacious and flexible third bedroom with a built-in office area, custom Murphy bed, generous storage, and floor-to-ceiling frameless windows and doors overlooking the terraced garden. A significant value-add: this property includes two parcels on a street-to-street lot (one APN), creating potential for an ADU with separate Florence Street accessideal for guests, extended family, an au pair suite, home office, or future income opportunity. With direct proximity to the iconic Dipsea Trail stairs, nearby parks, top-rated schools, and vibrant downtown Mill Valley, this home delivers an exceptional blend of privacy, elegance, and everyday livability for families who want both nature and community.

Days on Market

7 days

Current Status

Active

Original Price

$2,625,000

List Price

$2,625,000

On Market Date

Feb 16, 2026

Property Type

Single Family Residence

Area

Mill Valley

Zip Code

94941

MLS ID

326012284

APN

028-141-12

Year Built

1958

Stories in Building

Unavailable

Possession

Close Of Escrow

Data Source

BAREIS

Origin MLS System

Bed

3

Bath

3 (2/1)

Double Sinks, Low-Flow Toilet(s), Multiple Shower Heads, Radiant Heat, Soaking Tub, Stone, Tile

Parking

2

Detached, No Garage, Uncovered Parking Spaces 2+

SQ FT

2,080

SQ FT Source

Graphic Artist

Lot SQ FT

11,286.0

Lot Acres

0.2591 Acres

Kitchen

Granite Counter, Skylight(s)

Cooling

None

Dining Room

Formal Area

Living Room

Skylight(s)

Flooring

Stone, Tile, Wood

Foundation

Concrete Perimeter

Fire Place

Gas Log, Gas Starter, Living Room

Heating

Central, Gas

Laundry

Laundry Closet, Washer/Dryer Stacked Included

Main Level

Dining Room, Living Room, Partial Bath(s), Street Entrance

Views

Forest, Hills

Possession

Close Of Escrow

Basement

None

Architectural Style

Mid-Century

Fee

$0

MLS and other Information regarding properties for sale as shown in Theo have been obtained from various sources such as sellers, public records, agents and other third parties. This information may relate to the condition of the property, permitted or unpermitted uses, zoning, square footage, lot size/acreage or other matters affecting value or desirability. Unless otherwise indicated in writing, neither brokers, agents nor Theo have verified, or will verify, such information. If any such information is important to buyer in determining whether to buy, the price to pay or intended use of the property, buyer is urged to conduct their own investigation with qualified professionals, satisfy themselves with respect to that information, and to rely solely on the results of that investigation.

School data provided by GreatSchools. School service boundaries are intended to be used as reference only. To verify enrollment eligibility for a property, contact the school directly.