A steering column device includes a cylindrical inner tube, and a cylindrical outer tube which is fixed to the inner tube by being externally fitted to slide in an axial direction of the inner tube and being elastically reduced in diameter, wherein the outer tube is configured to have a first slit and a second slit to be reduced in diameter. A stress alleviation portion is provided at the second slit. A contour shape of the stress alleviation portion is set to include an elliptic arc-shaped portion of which a direction of a major axis is a direction intersecting the second slit.