An alpha-beta titanium alloy comprises, in weight percentages: an aluminum equivalency in the range of 2.0 to 10.0; a molybdenum equivalency in the range of 0 to 20.0; 0.3 to 5.0 cobalt; and titanium. In certain embodiments, the alpha-beta titanium alloy exhibits a cold working reduction ductility limit of at least 25%, a yield strength of at least 130 KSI (896.3 MPa), and a percent elongation of at least 10%. A method of forming an article comprising the cobalt-containing alpha-beta titanium alloy comprises cold working the cobalt-containing alpha-beta titanium alloy to at least a 25 percent reduction in cross-sectional area. The cobalt-containing alpha-beta titanium alloy does not exhibit substantial cracking during cold working.