Becici, on the Budva Riviera, is Montenegro's most consistently recognised Blue Flag beach. The Blue Flag programme certifies beaches for water quality, environmental management, safety, and facilities, so it's a reliable marker that a beach is clean and well maintained.
The number of Blue Flag sites in Montenegro has grown in recent years, and Slovenska Plaza in Budva and some beaches around Herceg Novi have also held the award in various seasons. Because certifications are renewed annually, it's worth checking the official Blue Flag website (blueflag.global) before your trip to see the current list.
For practical purposes, even non-certified beaches like Zanjic and Mirista on the Lustica Peninsula or the coves near Petrovac are noted for excellent water clarity and cleanliness — the certification matters most if you need a guaranteed standard of facilities alongside the water quality.