Using the isothermal-isobaric ensemble, exact equations of state are derived for three classical models of one-dimensional chain fluids. Each chain molecule is modeled by a series of linked sites which interact through nearest-neighbor bond potentials. In two of the models, the intramolecular bonds are modeled by infinitely deep square-well potentials, while in the third, the bonds are modeled by a harmonic potential. Intermolecular interactions are modeled by a hard-rod potential. Numerical results are presented for dimer and 8-mer fluids which illustrate the influence of chain length, well width and spring constant on the compressibility factor. The effect of adding an infinitely weak, infinitely longranged attractive interaction between the sites is also considered. The attractive tail induces a first-order phase transition of the gas-liquid type in all of the chain models. For certain values of the model parameters, however, two of the models show evidence of a second gas-liquid type transition, which appears to be associated with chain collapse.