Mashed potatoes are a Terran delicacy made from a potato, which is prepared simply by mashing a baked potato.

While stranded aboard Shuttlepod 1 in 2151, Charles Tucker ate a ration pack that consisted of meatloaf with gravy and mashed potatoes. (ENT: "Shuttlepod One")

Later that year, while stranded on the Torothan homeworld, Jonathan Archer offered to have Chef to make Tucker "a dinner you'll never forget," upon their return to the Enterprise. When asked what he wanted, Tucker stated that he wanted prime rib with a side of mashed potatoes, with mushroom gravy, with another side of broccoli, and for dessert, pecan pie. (ENT: "Desert Crossing")

When Kes underwent premature elogium due to space-dwelling lifeforms in 2371, she had an intense craving for certain foods. She ate six bowls of mashed potatoes with butter, a dish introduced to her by Samantha Wildman. When Neelix sampled her "snack", he found them unappealing. However, Kes neglected to mention that she had mixed in a container of nitrogenated soil. (VOY: "Elogium")

After taking his "handling fee" of two replicator rations from the Paris Radiogenic Sweepstakes, Tom Paris considered having prime rib with mashed potatoes and creamed spinach, along with some Yorkshire pudding and a raktajino with whipped cream on top. (VOY: "Meld")