HTML

Bootstrap 4 Navbar Dropdown Menu Items Right

Bootstrap 5 (update 2021)

Use the dropdown-menu-end class on the dropdown-menu to align the items inside the menu right..

    <div class="dropdown-menu dropdown-menu-end">
        <a class="dropdown-item" href="#">Link</a>
        <a class="dropdown-item" href="#">Link</a>
        <a class="dropdown-item" href="#">Link</a>
    </div>
https://codeply.com/p/kWLLKdjdpC

Bootstrap 4 (original answer)

Use the dropdown-menu-right class to align the items inside the menu right..

    <div class="dropdown-menu dropdown-menu-right text-right">
        <a class="dropdown-item" href="#">Link</a>
        <a class="dropdown-item" href="#">Link</a>
        <a class="dropdown-item" href="#">Link</a>
    </div>
http://codeply.com/go/6Mf9aK0P8G

Bootstrap 4 Navbar Dropdown Menu Items Right

    <div class="dropdown-menu dropdown-menu-end">
        <a class="dropdown-item" href="#">Link</a>
        <a class="dropdown-item" href="#">Link</a>
        <a class="dropdown-item" href="#">Link</a>
    </div>