Chemical investigation of the soft coral Clavularia koellikeri led to the isolation of fourteen new diterpenoid derivatives clavukellines A–N (1–14) featuring the dolabellane-type skeleton. Structural characterization of these compounds was accomplished through an integrated analytical strategy combining NMR spectroscopy and HR-ESI-MS. Absolute configurations were unambiguously assigned using ECD spectral simulation and DP4 + probability analysis. Preliminary pharmacological evaluation indicated that compounds 8 and 13 exhibited anti-inflammatory activity, while compounds 1–14 showed antithrombotic activity. This study reveals promising anti-inflammatory and antithrombotic potentials that warrant further investigation.