| 2016–17 National Division 1 East | |
| Date: | 3 September 2016 – 13 May 2017 |
| Champions: | Rhydyfelin (1st title) |
| Relegated: | Nantyglo Senghenydd |
| Matches: | 132 |
| Prevseason: | 2015–16 |
| Nextseason: | 2017–18 |
The 2016–17 WRU National Division 1 East was the third season of the new format of the WRU National Leagues. Previously, League 1 was the second tier of club rugby in Wales but since the creation of the WRU National Championship, League 1 is now the third tier. The league was won by Rhydyfelin and the bottom two clubs relegated to League 2 East were Nantyglo and Senghenydd.
Each team in the league will play each other twice on a home and away basis for a total of 22 matches played each. Points will be awarded in accordance to the standard scoring system in rugby union - 4 points for a win, 2 points for a draw and 0 for a loss. Teams will also be awarded 1 additional bonus point for scoring 4 or more tries in a match or losing by 7 points or less in a match. The team with the most points at the end of the season will be declared the winners. This season sees the return of the promotion play-off whereby the winning club will enter a play-off with the winner of Division 1 East Central to determine which club is to be promoted to the 2017-18 WRU Championship.
Last season's Champions Bedlinog were promoted to the Championship from League 1 East and bottom club Blackwood were relegated to Division 2 East. Last season's League 2 East Champions Abertillery Blaenau Gwent and runners-up Caerleon were promoted to the league.
The teams are:
The winners of both 1 East (Rhydyfelin) and 1 East Central (Treorchy) would play-off on a home and away basis to determine which club would be promoted. The winner would be the club who scores more points on aggregate.Rhydyfelin win 52-37 on aggregate and are promoted to the Championship.