An optical fiber made of silica glass includes a core having a maximum refractive index n1, a depressed portion surrounding the core and having an average refractive index n2, and cladding surrounding the depressed portion and having an average refractive index n3. In the optical fiber, n1>n3>n2. The optical fiber has a local maximum value of chromatic dispersion within a wavelength range of 1530 nm to 1610 nm, and the local maximum value is −2 ps/nm/km or greater and below 0 ps/nm/km.