A pet water bottle assembly comprising an upper bottle member and a cup member. An upstanding wall and an upwardly facing bottom surface of the cup member collectively define a reservoir adapted to hold liquid. The upstanding wall has a first circumferential wall portion with a first wall portion height and a second circumferential wall portion with a second wall portion height. The first wall portion height is greater than the second wall portion height to thereby provide a pet enhanced access to liquid within the reservoir when the cup member is tilted such that a top surface of liquid in the reservoir is level with the first axial extent. The cup member is adapted such that the upper bottle member snugly nests within the cup member.