An off-axis printhead assembly includes a printhead body that has an engagement element removably attachable to an attachment mechanism of a carriage of a printing system, the attachment mechanism of the carriage removably attachable to an on-axis printhead assembly. A fluid conduit interconnect is removably attached to the printhead body, the fluid conduit interconnect to connect to a fluid conduit to communicate printing fluid from at least one off-axis printing fluid supply through the fluid conduit interconnect to the printhead body.