Crude glycerin is a by-product of biodiesel production and has recently become more available as a livestock feed with the growth of the biofuel industry. Two experiments were conducted to evaluate the use of crude glycerin (GLY) as a feed ingredient in steam-flaked corn (SFC)-based growing diets fed to beef cattle. In Exp. 1, crossbred steers (n = 50; initial BW = 282 ± 2 kg) were used to determine the effects of GLY when included at 0, 2.5, 5, 7.5, and 10% of DM in a growing diet on cattle performance. In Exp. 2, crossbred steers (n = 54; initial BW = 283 ± 1 kg) were used to determine the effects of replacing SFC (REPSFC) or alfalfa hay (REPAH) with 7.5% GLY or a control diet without GLY (CON) on growing steer performance. In Exp. 1, final BW tended to respond in a quadratic manner (P = 0.09) in which it increased from 0 to 7.5% GLY and decreased from 7.5 to 10% GLY. Dry matter intake did not differ (P > 0.23), yet ADG responded quadratically (P = 0.04), where it increased from 0 to 7.5% GLY and decreased from 7.5 to 10% GLY. Feed efficiency (G:F) decreased linearly (P = 0.05) with increasing GLY concentration. In Exp. 2, final BW was greater for steers fed REPAH than CON or REPSFC (P = 0.04). Steers fed REPAH had a greater ADG than CON or REPSFC (P = 0.04). When GLY replaced SFC, ADG increased from 0 to 7.5% GLY where it was maximized before decreasing from 7.5 to 10% GLY inclusion. Replacing 7.5% of alfalfa hay (AH) in a growing diet with GLY can be beneficial to animal performance, which is likely the result of GLY being greater in energy than AH.