Lomseggi is a mountain on the border of Skjåk Municipality and Lom Municipality in Innlandet county, Norway. The 2068 m tall mountain is located in the Breheimen mountains and inside the Breheimen National Park, about 9 km southeast of the village of Bismo and about 10 km southwest of the village of Lom. The mountain is surrounded by several other notable mountains including Storhøi to the south; Lendfjellet, Moldulhøi, and Sandgrovhøi to the southwest; Hestdalshøgdi and Tverrfjellet to the west.