[Problem]Provided are a catheter holder that is capable of preventing an outer tube of a catheter from being caused to have a bending tendency due to the use of a holder tube, and holding the catheter in a stable state to prevent an unintentional load from being applied to each part of the catheter before use, and a catheter set including the catheter holder.[Means for Resolution]The catheter holder 10 includes an attachment section 20 configured to be attachable to a holder tube 200 that accommodates at least a portion of a sheath 110 of an image diagnosis catheter 100 in a wound state, a support section 30 extending from the attachment section in a direction away from the wound holder tube 200, and a fixing section 40 provided on a second end side of the support section, which is opposite to a first end side of the support section on which the attachment section is provided, and configured to fix a unit connector 150 and a hub 160 of the image diagnosis catheter to hold the outer tube 120, which is exposed from an opening portion of the holder tube 200, in a linear shape to be fixed in position.