#1 overall pick Casey Mize (Wareham '16). Photo from a 7/6/16 Wareham interview.
Sixteen former CCBL players were selected in the 2018 First-Year MLB Draft, including the first three overall picks. RHP Casey Mize (Wareham '16, Auburn) was selected first overall, catcher Joey Bart (Harwich '17, Georgia Tech) went second, and Alec Bohm (Falmouth '17, Wichita State) went third. See CapeCodBaseball.org for the full list of first-round selections.
For those keeping track, the CCBL seems to have had significantly more alumni selected in the MLB draft than any other collegiate summer league. The Northwoods League (previously blogged about) had one former player chosen in the first round.
In case you missed it, here's a video of Casey Mize being selected and below is a great tweet from him: