Yes, the dwarf planet Makemake has not yet been visited by any spacecraft as of 2023.
Other confirmed dwarf planets have been visited by passing probes. For example, Pluto, Ceres, and the Haumea system have been observed by flyby missions.
However, Makemake's distance from the Sun makes it a more challenging target. NASA is considering a flyby mission to Makemake, but no mission is currently scheduled.