55 Sunnyside Ave, Mill Valley, CA

Listing office Cushman & Wakefield | Larkspur Show Phone

Listing date Nov 25, 2025

Source Moodyscre

Displayed information is deemed reliable but is not guaranteed and should be independently verified.

All listing content including descriptions, pricing, images are the copyrighted material of Cushman & Wakefield | Larkspur

Report an issue

---

Overview

Available for the first time in over 30 years, 55 Sunnyside Ave presents a leasing opportunity in one of Mill Valley's iconic buildings. Formerly the Mill Valley post office, this property is situated in the heart of downtown. The location offers the potential to establish a brand presence. The property features vaulted ceilings and natural light. On-site parking is available. The property has a size of 7,082 square feet. The downtown location provides visibility.

Suggested Use

Food Market HVAC Service Cosmetic Store Parking Lot & Garage Nursing Home (Bike/Boat/Book/etc) Store Nursing Home Grocery & Convenience Store Bed & Breakfast Car Rental Facility

Zoning and permitted uses should be independently verified with local authorities.

Location Insight

• Map
• Local Demand

City

Mill Valley

County

Marin

State

California

Longitude

-122.545

Latitude

37.9063

Nearby Similar for Lease

• 

  $53 SF/Yr

  11,167 SF

  High-Identity Mill Valley Office Space

  Office space with views, convenient location, and modern amenities.

  61 Camino Alto, Mill Valley, CA 94941

  View Details
• 

  $5 SF/Yr

  1,098 SF

  Class A Office Building ForRent

  Three-story Class A office building with excellent freeway access.

  100 Shoreline Hwy, Mill Valley, CA

  View Details
• 

  $0.29 SF/Yr

  10,200 SF

  Mill Valley Office Space Available

  Second-floor office space suitable for medical or general office use.

  147 Lomita Drive, Mill Valley, CA 94941

  View Details
• 

  $2 SF/Yr

  Office Space with Freeway Access

  Exceptional office space in Mill Valley with convenient freeway access.

  591 Redwood Hwy, Mill Valley, CA 94941

  View Details
• 

  $4 SF/Yr

  Waterfront Office Space in Mill Valley

  Sublease opportunity: modern office with waterfront access, convenient location.

  591 Redwood highway, Mill Valley, CA 94941

  View Details
• 

  $60 SF/Yr

  Office Space Available For Rent

  Office space available for rent in Mill Valley, California.

  36 Tiburon Blvd, Mill Valley, CA 94941

  View Details
• 

  Contact for pricing

  3,840 SF

  Renovated Office Building with Views

  Two-story office building with recent renovations and abundant natural light.

  1058 Redwood Hwy Frontage Rd, Mill Valley, CA

  View Details
• 

  Contact for pricing

  2,725 SF

  Renovated Office Space with Views

  Mill Valley office space featuring modern amenities and freeway visibility.

  1 Belvedere Pl, Mill Valley, CA

  View Details
• 

  Contact for pricing

  1,000 SF

  Mill Valley Office Space Available

  Office space for rent in Mill Valley, CA.

  91 E Blithedale Ave, Mill Valley, CA

  View Details
• 

  Contact for pricing

  1,840 SF

  Renovated Creative Office Space Available

  Creative office space for lease, fully renovated with parking.

  1060 Redwood Hwy Frontage Rd, Mill Valley, CA

  View Details
• 

  Contact for pricing

  Redwood and Glass Office Building

  Office space for lease near San Francisco International Airport.

  495 Miller Ave, Mill Valley, CA 94941

  View Details
• 

  Contact for pricing

  Office Space For Rent

  Office space available for lease in Mill Valley, California.

  20 Sunnyside Ave, #E, Mill Valley, CA 94941

  View Details

FAQs

What type of property is this?

Office building - Former Mill Valley post office available for lease.

Where is this office building located?

The property is located at 55 Sunnyside Ave Mill Valley, CA.

What are key features of this property?

This property features: Unparalleled downtown location and visibility in the heart of Mill Valley.; Rare opportunity to lease an iconic building, available for the first time in 30+ years.; The former Mill Valley post office, a recognizable and historic landmark.