On May 2, 2015, Hewitt signed with the Miami Dolphins as an undrafted free agent following the conclusion of the 2015 NFL draft.

[4] On January 3, 2016, Hewitt made a season-high six tackles and one pass breakup against the New England Patriots.

[14] In Week 1 against the Bills, Hewitt intercepted Josh Allen once as the Jets lost 17–16.

[16] In Week 11 against the Redskins, Hewitt intercepted a pass thrown by quarterback Dwayne Haskins in the 34–17 win.

[18] He started all 16 games, leading the team with a career-high 134 tackles, along with 2.0 sacks, four passes defensed, and one interception.

On March 30, 2022, Hewitt re-signed with the Texans, playing almost exclusively on special teams that season.

[22] Media related to Neville Hewitt (American football) at Wikimedia Commons