Sinus Honoris[1] /ˈsaɪnəs (h)ɒˈnɔːrɪs/ (Latin sinus honōris "Bay of Honour") is located along the western edge of the Mare Tranquillitatis located on the surface of the near side of the Moon.

The selenographic coordinates of this feature are 11.7° N, 17.9° E. It has a diameter of 112 km.

[1] Sinus Honoris has a wide mouth and is bordered by uneven terrain to the north and southwest.

Where the bay joins the mare, rille systems extend to the north and south.

At the west end of the bay is a finger of mare surface that extends to the northwest for almost 100 km.