A steering column support construction, comprising: a displacement-side bracket or supported plate sections (21a; 21b) that is fastened to a top side portion of a middle section of a steering column (6a;6b); a vehicle-side bracket (23;23a;23b;23c) that has a locking notch (34a; 34b) or through hole (53; 64) extending in the forward-backward direction and formed in a middle section in a width direction of the vehicle-side bracket that is fastened to a vehicle body side in at least two locations on both sides in the width direction of the locking notch or through hole and that is not displaced forward even during a secondary collision; a column-side bracket having a pair of left and right support plate sections that are located on both sides of the displacement-side bracket; a locking member that together with being fastened to the column-side bracket, engages with the locking notch or through hole; an adjustment rod that, with the displacement-side bracket held between the support plate sections, is inserted in the width direction through the displacement side-bracket and is spanned between the support plate sections; and a pair of pressure sections (28, 31) that are provided on both end sections of the adjustment rod; and fastening and adjustment of the displacement bracket with respect to the column-side bracket being enabled by expanding or contracting a space between the pressure sections, and the column-side bracket and locking member being supported with respect to the vehicle-side bracket so as to be able to break away in a forward direction thereof due to an impact load caused by the secondary collision. a displacement-side bracket or supported plate sections (21a; 21b) that is fastened to a top side portion of a middle section of a steering column (6a;6b); a vehicle-side bracket (23;23a;23b;23c) that has a locking notch (34a; 34b) or through hole (53; 64) extending in the forward-backward direction and formed in a middle section in a width direction of the vehicle-side bracket that is fastened to a vehicle body side in at least two locations on both sides in the width direction of the locking notch or through hole and that is not displaced forward even during a secondary collision; a column-side bracket having a pair of left and right support plate sections that are located on both sides of the displacement-side bracket; a locking member that together with being fastened to the column-side bracket, engages with the locking notch or through hole; an adjustment rod that, with the displacement-side bracket held between the support plate sections, is inserted in the width direction through the displacement side-bracket and is spanned between the support plate sections; and a pair of pressure sections (28, 31) that are provided on both end sections of the adjustment rod; and fastening and adjustment of the displacement bracket with respect to the column-side bracket being enabled by expanding or contracting a space between the pressure sections, and the column-side bracket and locking member being supported with respect to the vehicle-side bracket so as to be able to break away in a forward direction thereof due to an impact load caused by the secondary collision.