An OCT data processing device includes a processor that performs acquiring three-dimensional OCT data. The three-dimensional OCT data is OCT data of a tissue of a subject's eye acquired by an OCT device and is obtained by irradiating measurement light on a two-dimensional measurement region. The two-dimensional measurement region extends in a direction intersecting an optical axis of the measurement light. The processor further preforms setting a line pattern, from among a plurality of types of line pattern, with respect to the two-dimensional measurement region for which the three-dimensional OCT data is obtained, at least one of an arrangement, a number, or a shape of one or more lines being different for the plurality of types of line pattern, and extracting, from the three-dimensional OCT data, a two-dimensional tomographic image of a cross section intersecting each of the one or more lines of the set line pattern.
