Biopolymer-based matrices such as Matrigel, collagen, and fibrin hydrogels are the current gold standard for 3-D cell culture. Few bioinks suitable for extrusion-based bioprinting support cell spreading, migration, and proliferation to a similar degree as these traditional matrices. Here, we mechanically, structurally, and biologically characterize a novel bioink based on methacrylated collagen (ColMA) at concentrations of 2.5, 3.5, and 4.5 mg/ml, combined with thiolated hyaluronic acid (HASH) as a viscous background fluid, and a light-activated photoinitiator (LAP) for crosslinking. ColMA-HASH forms collagen networks with pore sizes ranging from 4 to 25 µm, depending on collagen concentration, polymerization temperature, and light activation protocol. The highly viscous background fluid (HA) stabilizes the bioink after bioprinting until the light-activated crosslinking reaction takes effect, resulting in hydrogels that are soft (200–600 Pa), highly viscoelastic (power-law fluidity of 0.2–0.45), and exhibit strain-stiffening behavior similar to pure collagen biopolymers, sustaining strains up to 30% before yielding. At the lowest collagen concentration (2.5 mg/ml), breast carcinoma cells show rapid spreading within 24 hours post-printing, migration speeds of >10 µm/h, and robust proliferation. In summary, ColMA-HASH is an excellent bioink for extrusion-based bioprinting, offering superior biological properties and mechanical characteristics comparable to traditional biopolymer-based matrices.