SharePoint Online: PowerShell to Get Site Collection Administrators

#Load SharePoint CSOM Assemblies
Add-Type -Path "C:\Program Files\SharePoint Online Management Shell\Microsoft.Online.SharePoint.PowerShell\Microsoft.SharePoint.Client.dll"
Add-Type -Path "C:\Program Files\SharePoint Online Management Shell\Microsoft.Online.SharePoint.PowerShell\Microsoft.SharePoint.Client.Runtime.dll"
Add-Type -Path "C:\Program Files\SharePoint Online Management Shell\Microsoft.Online.SharePoint.PowerShell\Microsoft.Online.SharePoint.Client.Tenant.dll"
  
#Get Primary Owners of All Site collections from the Tenant
Function Get-SPOPrimarySiteOwners($AdminSiteURL, $Cred)
{
    #Setup credentials to connect
    $Credentials = New-Object Microsoft.SharePoint.Client.SharePointOnlineCredentials($Cred.Username, $Cred.Password)
   
    #Setup the context
    $Ctx = New-Object Microsoft.SharePoint.Client.ClientContext($AdminSiteURL)
    $Ctx.Credentials = $Credentials
  
    #Get the tenant object 
    $Tenant = New-Object Microsoft.Online.SharePoint.TenantAdministration.Tenant($ctx)
  
    #Get All Site Collections
    $SiteCollections=$Tenant.GetSitePropertiesFromSharePoint(0,$true)
    $Ctx.Load($SiteCollections)
    $Ctx.ExecuteQuery()
 
    #Iterate through Each site collection
    ForEach($Site in $SiteCollections)
    {
        #Get the Site Collection and Audit Objects
        $Ctx = New-Object Microsoft.SharePoint.Client.ClientContext($Site.URL)
        $Ctx.Credentials = $Credentials
        
        #Get the Site collection
        $SiteCollection = $Ctx.Site
        $Ctx.Load($SiteCollection)
        $Ctx.ExecuteQuery()
 
        #Get Site Owner
        $Owner = $SiteCollection.Owner
        $Ctx.Load($Owner)
        $Ctx.ExecuteQuery()
        
        #Output Primary Site owner Details
        $SiteCollection | Select URL, @{Name="Owner Name";Expression={$_.Owner.Title}}, @{Name="Owner Email";Expression={$_.Owner.Email}}
    }
}
  
#Set Parameters
$AdminSiteUrl = "https://Crescent-admin.sharepoint.com/"
$Cred= Get-Credential
 
Get-SPOPrimarySiteOwners -AdminSiteURL $AdminSiteUrl -Cred $Cred

#Variables for processing
$AdminURL = "https://Crescent-admin.sharepoint.com/"
$AdminName = "SPAdmin@Crescent.com"
$SiteCollURL="https://Crescent.sharepoint.com/sites/sales"
 
#User Names Password to connect 
$Password = Read-host -assecurestring "Enter Password for $AdminName" 
$Credential = new-object -typename System.Management.Automation.PSCredential -argumentlist $AdminName, $Password

#Connect to SharePoint Online
Connect-SPOService -url $AdminURL -credential $Credential

#Get the Site colection
$SiteColl = Get-SPOSite $SiteCollURL
    
#sharepoint online powershell get all site collection admins
$SiteAdmins = Get-SPOUser -Site $SiteCollURL -Limit ALL | Where { $_.IsSiteAdmin -eq $True}
foreach($Admin in $SiteAdmins)
{
    Write-host $Admin.LoginName        
}

#Variables for processing
$AdminURL = "https://Crescent-admin.sharepoint.com"
$AdminName = "spadmin@Crescent.com"
 
#User Names Password to connect 
$Password = Read-host -assecurestring "Enter Password for $AdminName" 
$Credential = new-object -typename System.Management.Automation.PSCredential -argumentlist $AdminName, $Password

Try {
    #Connect to SharePoint Online
    Connect-SPOService -url $AdminURL -credential $Credential

    #Get all Site colections
    $Sites = Get-SPOSite -Limit ALL

    Foreach ($Site in $Sites)
    {
        Write-host $Site.URL
    
        #Get all Site Collection Administrators
        $SiteAdmins = Get-SPOUser -Site $Site.Url -Limit ALL | Where { $_.IsSiteAdmin -eq $True}
        foreach($Admin in $SiteAdmins)
        {
            Write-host $Admin.LoginName        
        }
    }
}
catch {
    write-host "Error: $($_.Exception.Message)" -foregroundcolor Red
}

#Set Variables
$SiteURL = "https://crescent.sharepoint.com/sites/Marketing"

#Connect to PnP Online
Connect-PnPOnline -Url $SiteURL -Credentials (Get-Credential)

#Get Site Collection Administrators
Get-PnPSiteCollectionAdmin

#Set Variables
$SiteURL = "https://crescent.sharepoint.com"

#Get Credentials to connect
$Cred = Get-Credential

#Connect to PnP Online
Connect-PnPOnline -Url $SiteURL -Credentials $Cred

#Get All Site collections  
$SitesCollection = Get-PnPTenantSite

#Loop through each site collection
ForEach($Site in $SitesCollection)  
{  
    Write-host -F Green "Site Collection Administrators of site: " $Site.Url  
    Connect-PnPOnline -Url $Site.Url -Credentials $Cred
  
    #Get Site Collection administrators of the site
    Get-PnPSiteCollectionAdmin
}

#Set Variables
$AdminSiteURL = "https://crescent-admin.sharepoint.com"
 
#Connect to Admin Center
Connect-PnPOnline -Url $AdminSiteURL -Interactive
  
#Get All Site collections - Exclude: Seach Center, Mysite Host, App Catalog, Redirect, Content Type Hub, eDiscovery and Bot Sites
$SiteCollections = Get-PnPTenantSite | Where -Property Template -NotIn ("SRCHCEN#0", "REDIRECTSITE#0", "SPSMSITEHOST#0", "APPCATALOG#0", "POINTPUBLISHINGHUB#0", "EDISC#0", "STS#-1")
 
#Loop through each site collection
ForEach($Site in $SiteCollections) 
{ 
    Write-host -F Yellow "Getting Site Collection Administrators of the site: " $Site.Url 
    Connect-PnPOnline -Url $Site.Url -Interactive
    
    #Get Site Collection Administrators
    $SiteAdminstrators = @()
    Get-PnPSiteCollectionAdmin -PipelineVariable Admin | ForEach-Object {
        If($_.PrincipalType -eq "SecurityGroup")
        {
            #Get Members of the Group
            $Group = Get-PnPMicrosoft365Group -IncludeOwners | Where {$_.Mail -eq $Admin.Email}
            $Group.Owners | Select Email | ForEach-Object {
                $SiteAdminstrators += $_.Email
            }
        }
        Else
        {
            $SiteAdminstrators += $Admin.Email
        }
    }
    #Get Site Collection Administrators of the Site
    $SiteAdminstrators | select -Unique
}