Yes, a tomato is considered an organ.
Botanically speaking, a fruit is the seed-bearing product that grows from the ovary of a flowering plant. Tomatoes, being fruits, are derived from the flower's ovary and contain seeds.
Organs, in biology, are composed of different tissues that work together to perform a specific function. The tomato, as a fruit, contains various tissues like the pericarp, which is divided into the exocarp (outer layer), mesocarp (middle layer), and endocarp (inner layer). Each of these tissues has a specific role in protecting the seeds and attracting animals for seed dispersal.
Therefore, based on its structure and function, a tomato qualifies as an organ.