Office 365: How to add a user/group as Site Collection Administrator in SPO using PowerShell!

This time I’m sharing a PowerShell script that allows to add a new site collection administrator to an existing SharePoint Online (SPO) site collection. The script uses client side object model to add a single user, an Office 365 Group or a Security Group as Site Collection administrator. You can download the script from the following URL: How to add a site collection administrator to a SPO Site Collection

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#Script that allows to add a new Site Collection Administrator to an existing Site Collection. It is possible to add an individual user,

#a security group or an Office 365 Group as Site Collection Administrator

# Required Parameters:

#  -> $sUserName: User Name to connect to the SharePoint Online Site Collection.

#  -> $sPassword: Password for the user.

#  -> $sCSOMPath: CSOM Assemblies Path.

#  -> $sSiteUrl: SharePoint Online Site Url.

#  -> $sNewSiteCollectionAdministrator: New Site Collection Administrator to be added to the Site Collection.

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$host.Runspace.ThreadOptions = "ReuseThread"

#Definition of the function that allows to add a new Site Collection Administrator to a SPO Site Collection

function Set-SPOSiteCollectionAdministrator

{

    param ($sCSOMPath,$sSiteUrl,$sUserName,$sPassword,$sNewSiteCollectionAdministrator)

    try

    {   

        #Adding the Client OM Assemblies        

        $sCSOMRuntimePath=$sCSOMPath +  "\Microsoft.SharePoint.Client.Runtime.dll"        

        $sCSOMPath=$sCSOMPath +  "\Microsoft.SharePoint.Client.dll"             

        Add-Type -Path $sCSOMPath         

        Add-Type -Path $sCSOMRuntimePath       

        #SPO Client Object Model Context

        $spoCtx = New-Object Microsoft.SharePoint.Client.ClientContext($sSiteUrl)

        $spoCredentials = New-Object Microsoft.SharePoint.Client.SharePointOnlineCredentials($sUserName, $sPassword)  

        $spoCtx.Credentials = $spoCredentials      

        Write-Host "------------------------------------------------------------------------------------------"  -foregroundcolor Green

        Write-Host "Addding $sNewSiteCollectionAdministrator as Site Collection Administartor in $sSiteUrl !!" -ForegroundColor Green

        Write-Host "------------------------------------------------------------------------------------------"  -foregroundcolor Green        

        $spoUser=$spoCtx.Web.EnsureUser($sNewSiteCollectionAdministrator)

        $spoUser.IsSiteAdmin=$true

        $spoUser.Update()

        $spoCtx.Load($spoUser)

        $spoCtx.ExecuteQuery()

        Write-Host "------------------------------------------------------------------------------------------"  -foregroundcolor Green

        Write-Host "$sNewSiteCollectionAdministrator added as Site Collection Administartor in $sSiteUrl !!" -ForegroundColor Green

        Write-Host "------------------------------------------------------------------------------------------"  -foregroundcolor Green    

        $spoCtx.Dispose()

    }

    catch [System.Exception]

    {

        Write-Host -ForegroundColor Red $_.Exception.ToString()   

    }    

}

#Required Parameters

$sSiteUrl = "https://<O365Domain>.sharepoint.com/<SPO_Site>"

$sUserName = "<UserName><O365Domain>.onmicrosoft.com" 

#$sPassword = Read-Host -Prompt "Enter your password: " -AsSecureString  

$sPassword=ConvertTo-SecureString "<UserPassword>" -AsPlainText -Force

$sCSOMPath="<SPO_Path>"

$sNewSiteCollectionAdministrator="<UserLogin/SecurityGroupName/Office365GroupName"

Set-SPOSiteCollectionAdministrator -sCSOMPath $sCSOMPath -sSiteUrl $sSiteUrl -sUserName $sUserName -sPassword $sPassword -sNewSiteCollectionAdministrator $sNewSiteCollectionAdministrator

And the following is the nice result you will get once you execute the script in PowerShell ISE or Visual Studio 2015: