A high chair is convertible into multiple operative configurations to provide flexibility in utilization. The high chair includes a youth chair having a seat member affixed to a Z-shaped frame. A booster seat including a reclining seat back is mountable on the seat member such that the seat member is nested within the booster seat. A latch mechanism carried by the booster seat secures the booster seat to the seat member. A separate base member can also be nested into the bottom of the booster seat so that the booster seat can be utilized on a standard chair. The tray is mountable into the booster seat so that the tray can be utilized therewith irrespective of whether the booster seat is used in a high chair configuration or a booster seat configuration. The Z-frame incorporates telescopic support legs to define height adjustment for the high chair.