We report infrared (IR) spectra of HOCS+, HSCO+, t-HOCS, and other species produced on electron bombardment of a mixture of carbonyl sulfide (OCS) and para-hydrogen (p-H2) during deposition at 3.2 K. After maintenance of the matrix in darkness for 15 h, the intensities of absorption features of HOCS+ at 2945.9 (ν1), 1875.3 (ν2), and 1041.9 (ν3) cm-1 and those of HSCO+ at 2506.9 (ν1) and 2074.2 (ν2) cm-1 decreased through neutralization with trapped electrons. Lines observed at 3563.4, 1394.8, and 1199.0 cm-1, which decreased slightly in intensity after maintenance in darkness and were nearly depleted after irradiation at 373 nm, are assigned to a t-HOCS radical. The corresponding spectra of their 13C- and D-isotopologues were observed. The IR spectra of HSCO+ and t-HOCS and those of modes ν2 and ν3 of HOCS+ are new. The assignments were made according to the expected chemical behavior and a comparison of experimental and calculated wavenumbers and 13C- and D-isotopic shifts. The wavenumber of the OH stretching mode (2945.9 cm-1) of HOCS+ in solid p-H2 is significantly red-shifted from that (3435.16 cm-1) reported for gaseous HOCS+; this shift is attributed to partial sharing of a proton between OCS and H2. The corresponding p-H2 induced shift is small in HSCO+ because of a much weaker interaction between HSCO+ and H2.