| 400 Building | |
| Status: | Completed |
| Structural System: | Reinforced concrete |
| Ren Cost: | > $1 million |
| Owner: | Washington Federal Bank |
| Landlord: | Unico Properties |
| Address: | 400 108th Avenue NE |
| Location Town: | Bellevue, Washington |
| Location Country: | United States |
| Coordinates: | 47.614°N -122.196°W |
| Start Date: | 1966 |
| Completion Date: | 1967 |
| Renovation Date: | 2007–2010 |
| Height: | 92feet |
| Floor Count: | 7 |
| Floor Area: | 75000ft2 |
| Architecture Firm: | Parr, Roderick, and Associates |
| Highest Region: | Bellevue |
| Highest Reflabel: | archdb |
| Highest Prev: | Puget Power Building |
| Highest Start: | 1967 |
| Highest End: | 1970 |
| Highest Next: | Paccar Tower |
The 400 Building, also known as the First Mutual Center and Washington Federal Center, is a seven story tall building in Bellevue, Washington. When it was completed in 1967, it was the tallest building in Bellevue.