This study documents repeated observations of octopuses occupying the same den across multiple sites in San Diego County. Although octopuses are generally considered solitary, co-denning was observed on multiple occasions, including both same-sex and mixed-sex pairings. Observations were collected during SCUBA surveys conducted between March and August 2026, with den occupancy recorded during both collection and non-collection dives. Because only animals visible to divers could be documented, observed co-denning represents a minimum estimate of shared-den use. These findings provide evidence that den sharing may occur more frequently than previously recognized and suggest that social tolerance in octopuses may be more flexible than traditionally assumed.