diff --git a/.dialyzer-ignore b/.dialyzer-ignore
index b4de7e82a0..11bb3be729 100644
--- a/.dialyzer-ignore
+++ b/.dialyzer-ignore
@@ -3,4 +3,5 @@
 :0: Unknown type 'Elixir.Map':t/0
 apps/ethereum_jsonrpc/lib/ethereum_jsonrpc.ex:400: Function timestamp_to_datetime/1 has no local return
 apps/explorer/lib/explorer/repo/prometheus_logger.ex:8: Function microseconds_time/1 has no local return
-apps/explorer/lib/explorer/repo/prometheus_logger.ex:8: The call 'Elixir.System':convert_time_unit(__@1::any(),'native','microseconds') breaks the contract (integer(),time_unit() | 'native',time_unit() | 'native') -> integer()
\ No newline at end of file
+apps/explorer/lib/explorer/repo/prometheus_logger.ex:8: The call 'Elixir.System':convert_time_unit(__@1::any(),'native','microseconds') breaks the contract (integer(),time_unit() | 'native',time_unit() | 'native') -> integer()
+apps/block_scout_web/lib/block_scout_web/views/layout_view.ex:162: The call 'Elixir.Poison.Parser':'parse!'(any(),#{'keys':='atoms!'}) will never return since the success typing is (binary() | maybe_improper_list(binary() | maybe_improper_list(any(),binary() | []) | byte(),binary() | []),[{atom(),_}]) -> 'false' | 'nil' | 'true' | binary() | ['false' | 'nil' | 'true' | binary() | [any()] | number() | map()] | number() | map() and the contract is (iodata(),'Elixir.Keyword':t()) -> t()
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
index deeba161c6..a29f0440e3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -40,6 +40,7 @@
 
 - [#1814](https://github.com/poanetwork/blockscout/pull/1814) - Clear build artefacts script
 - [#1837](https://github.com/poanetwork/blockscout/pull/1837) - Add -f flag to clear_build.sh script delete static folder
+- [#1900](https://github.com/poanetwork/blockscout/pull/1900) - SUPPORTED_CHAINS ENV var
 - [#1892](https://github.com/poanetwork/blockscout/pull/1892) - Remove temporary worker modules
 
 ## 1.3.10-beta
diff --git a/apps/block_scout_web/config/config.exs b/apps/block_scout_web/config/config.exs
index 78b887b122..f38ed779b5 100644
--- a/apps/block_scout_web/config/config.exs
+++ b/apps/block_scout_web/config/config.exs
@@ -28,65 +28,7 @@ config :block_scout_web,
     "EtherChain" => "https://www.etherchain.org/",
     "Bloxy" => "https://bloxy.info/"
   },
-  other_networks: [
-    %{
-      title: "POA Core",
-      url: "https://blockscout.com/poa/core"
-    },
-    %{
-      title: "POA Sokol",
-      url: "https://blockscout.com/poa/sokol",
-      test_net?: true
-    },
-    %{
-      title: "xDai Chain",
-      url: "https://blockscout.com/poa/dai"
-    },
-    %{
-      title: "Ethereum Mainnet",
-      url: "https://blockscout.com/eth/mainnet"
-    },
-    %{
-      title: "Kovan Testnet",
-      url: "https://blockscout.com/eth/kovan",
-      test_net?: true
-    },
-    %{
-      title: "Ropsten Testnet",
-      url: "https://blockscout.com/eth/ropsten",
-      test_net?: true
-    },
-    %{
-      title: "Goerli Testnet",
-      url: "https://blockscout.com/eth/goerli",
-      test_net?: true
-    },
-    %{
-      title: "Rinkeby Testnet",
-      url: "https://blockscout.com/eth/rinkeby",
-      test_net?: true
-    },
-    %{
-      title: "Ethereum Classic",
-      url: "https://blockscout.com/etc/mainnet",
-      other?: true
-    },
-    %{
-      title: "Aerum Mainnet",
-      url: "https://blockscout.com/aerum/mainnet",
-      other?: true
-    },
-    %{
-      title: "Callisto Mainnet",
-      url: "https://blockscout.com/callisto/mainnet",
-      other?: true
-    },
-    %{
-      title: "RSK Mainnet",
-      url: "https://blockscout.com/rsk/mainnet",
-      other?: true
-    }
-  ]
+  other_networks: System.get_env("SUPPORTED_CHAINS")
 
 config :block_scout_web, BlockScoutWeb.Counters.BlocksIndexedCounter, enabled: true
 
diff --git a/apps/block_scout_web/lib/block_scout_web/templates/layout/_footer.html.eex b/apps/block_scout_web/lib/block_scout_web/templates/layout/_footer.html.eex
index 09b5aabf05..b03b9f964f 100644
--- a/apps/block_scout_web/lib/block_scout_web/templates/layout/_footer.html.eex
+++ b/apps/block_scout_web/lib/block_scout_web/templates/layout/_footer.html.eex
@@ -37,7 +37,7 @@
           <li><a href="https://forum.poa.network/c/blockscout" rel="noreferrer" class="footer-link"><%= gettext("Support") %></a></li>
         </ul>
       </div>
-      <% main_nets = main_nets() %>
+      <% main_nets = main_nets(other_networks()) %>
 
       <%= unless Enum.empty?(main_nets) do %>
         <div class="col-md-<%= col_size %> footer-list">
@@ -50,7 +50,7 @@
         </div>
       <% end %>
 
-      <% test_nets = test_nets() %>
+      <% test_nets = test_nets(other_networks()) %>
 
       <%= unless Enum.empty?(test_nets) do %>
         <div class="col-md-<%= col_size %> footer-list">
diff --git a/apps/block_scout_web/lib/block_scout_web/templates/layout/_topnav.html.eex b/apps/block_scout_web/lib/block_scout_web/templates/layout/_topnav.html.eex
index f7392a6b39..514422bcc8 100644
--- a/apps/block_scout_web/lib/block_scout_web/templates/layout/_topnav.html.eex
+++ b/apps/block_scout_web/lib/block_scout_web/templates/layout/_topnav.html.eex
@@ -85,15 +85,15 @@
           </a>
           <div class="dropdown-menu" aria-labelledby="navbarDropdown">
             <a class="dropdown-item header division">Mainnets</a>
-            <%= for %{url: url, title: title} <- head_main_nets() do %>
+            <%= for %{url: url, title: title} <- dropdown_head_main_nets() do %>
               <a class="dropdown-item" href="<%= url%>"><%= title %></a>
             <% end %>
             <a class="dropdown-item header division">Testnets</a>
-            <%= for %{url: url, title: title} <- test_nets() do %>
+            <%= for %{url: url, title: title} <- test_nets(dropdown_nets()) do %>
               <a class="dropdown-item" href="<%= url%>"><%= title %></a>
             <% end %>
             <a class="dropdown-item header division">Other networks</a>
-            <%= for %{url: url, title: title} <- other_nets() do %>
+            <%= for %{url: url, title: title} <- dropdown_other_nets() do %>
               <a class="dropdown-item" href="<%= url%>"><%= title %></a>
             <% end %>
           </div>
diff --git a/apps/block_scout_web/lib/block_scout_web/views/layout_view.ex b/apps/block_scout_web/lib/block_scout_web/views/layout_view.ex
index c4e17bc2f1..7a454a0e72 100644
--- a/apps/block_scout_web/lib/block_scout_web/views/layout_view.ex
+++ b/apps/block_scout_web/lib/block_scout_web/views/layout_view.ex
@@ -2,8 +2,68 @@ defmodule BlockScoutWeb.LayoutView do
   use BlockScoutWeb, :view
 
   alias Plug.Conn
+  alias Poison.Parser
 
   @issue_url "https://github.com/poanetwork/blockscout/issues/new"
+  @default_other_networks [
+    %{
+      title: "POA Core",
+      url: "https://blockscout.com/poa/core"
+    },
+    %{
+      title: "POA Sokol",
+      url: "https://blockscout.com/poa/sokol",
+      test_net?: true
+    },
+    %{
+      title: "xDai Chain",
+      url: "https://blockscout.com/poa/dai"
+    },
+    %{
+      title: "Ethereum Mainnet",
+      url: "https://blockscout.com/eth/mainnet"
+    },
+    %{
+      title: "Kovan Testnet",
+      url: "https://blockscout.com/eth/kovan",
+      test_net?: true
+    },
+    %{
+      title: "Ropsten Testnet",
+      url: "https://blockscout.com/eth/ropsten",
+      test_net?: true
+    },
+    %{
+      title: "Goerli Testnet",
+      url: "https://blockscout.com/eth/goerli",
+      test_net?: true
+    },
+    %{
+      title: "Rinkeby Testnet",
+      url: "https://blockscout.com/eth/rinkeby",
+      test_net?: true
+    },
+    %{
+      title: "Ethereum Classic",
+      url: "https://blockscout.com/etc/mainnet",
+      other?: true
+    },
+    %{
+      title: "Aerum Mainnet",
+      url: "https://blockscout.com/aerum/mainnet",
+      other?: true
+    },
+    %{
+      title: "Callisto Mainnet",
+      url: "https://blockscout.com/callisto/mainnet",
+      other?: true
+    },
+    %{
+      title: "RSK Mainnet",
+      url: "https://blockscout.com/rsk/mainnet",
+      other?: true
+    }
+  ]
 
   alias BlockScoutWeb.SocialMedia
 
@@ -95,29 +155,47 @@ defmodule BlockScoutWeb.LayoutView do
   def ignore_version?(_), do: false
 
   def other_networks do
-    :block_scout_web
-    |> Application.get_env(:other_networks, [])
+    get_other_networks =
+      if Application.get_env(:block_scout_web, :other_networks) do
+        :block_scout_web
+        |> Application.get_env(:other_networks)
+        |> Parser.parse!(%{keys: :atoms!})
+      else
+        @default_other_networks
+      end
+
+    get_other_networks
     |> Enum.reject(fn %{title: title} ->
       title == subnetwork_title()
     end)
     |> Enum.sort()
   end
 
-  def main_nets do
-    Enum.reject(other_networks(), &Map.get(&1, :test_net?))
+  def main_nets(nets) do
+    nets
+    |> Enum.reject(&Map.get(&1, :test_net?))
   end
 
-  def head_main_nets do
-    main_nets()
-    |> Enum.reject(&Map.get(&1, :other?))
+  def test_nets(nets) do
+    nets
+    |> Enum.filter(&Map.get(&1, :test_net?))
   end
 
-  def test_nets do
-    Enum.filter(other_networks(), &Map.get(&1, :test_net?))
+  def dropdown_nets do
+    other_networks()
+    |> Enum.reject(&Map.get(&1, :hide_in_dropdown?))
+  end
+
+  def dropdown_head_main_nets do
+    dropdown_nets()
+    |> main_nets()
+    |> Enum.reject(&Map.get(&1, :other?))
   end
 
-  def other_nets do
-    Enum.filter(other_networks(), &Map.get(&1, :other?))
+  def dropdown_other_nets do
+    dropdown_nets()
+    |> main_nets()
+    |> Enum.filter(&Map.get(&1, :other?))
   end
 
   def other_explorers do
diff --git a/apps/block_scout_web/test/block_scout_web/views/layout_view_test.exs b/apps/block_scout_web/test/block_scout_web/views/layout_view_test.exs
index fd26390c2b..5e3302ceec 100644
--- a/apps/block_scout_web/test/block_scout_web/views/layout_view_test.exs
+++ b/apps/block_scout_web/test/block_scout_web/views/layout_view_test.exs
@@ -86,4 +86,123 @@ defmodule BlockScoutWeb.LayoutViewTest do
                 ~s(<a href="https://github.com/poanetwork/blockscout/releases/tag/v1.3.4-beta" class="footer-link" target="_blank">1.3.4</a>)}
     end
   end
+
+  @supported_chains_pattern ~s([ { "title": "RSK Mainnet", "url": "https://blockscout.com/rsk/mainnet", "other?": true }, { "title": "POA Sokol", "url": "https://blockscout.com/poa/sokol", "test_net?": true }, { "title": "POA Core", "url": "https://blockscout.com/poa/core" }, { "title": "LUKSO L14 testnet", "url": "https://blockscout.com/lukso/l14", "test_net?": true, "hide_in_dropdown?": true } ])
+
+  describe "other_networks/0" do
+    test "get networks list based on env variables" do
+      Application.put_env(:block_scout_web, :other_networks, @supported_chains_pattern)
+
+      assert LayoutView.other_networks() == [
+               %{
+                 title: "POA Core",
+                 url: "https://blockscout.com/poa/core"
+               },
+               %{
+                 title: "RSK Mainnet",
+                 url: "https://blockscout.com/rsk/mainnet",
+                 other?: true
+               },
+               %{
+                 title: "POA Sokol",
+                 url: "https://blockscout.com/poa/sokol",
+                 test_net?: true
+               },
+               %{
+                 title: "LUKSO L14 testnet",
+                 url: "https://blockscout.com/lukso/l14",
+                 test_net?: true,
+                 hide_in_dropdown?: true
+               }
+             ]
+    end
+  end
+
+  describe "main_nets/1" do
+    test "get all main networks list based on env variables" do
+      Application.put_env(:block_scout_web, :other_networks, @supported_chains_pattern)
+
+      assert LayoutView.main_nets(LayoutView.other_networks()) == [
+               %{
+                 title: "POA Core",
+                 url: "https://blockscout.com/poa/core"
+               },
+               %{
+                 title: "RSK Mainnet",
+                 url: "https://blockscout.com/rsk/mainnet",
+                 other?: true
+               }
+             ]
+    end
+  end
+
+  describe "test_nets/1" do
+    test "get all networks list based on env variables" do
+      Application.put_env(:block_scout_web, :other_networks, @supported_chains_pattern)
+
+      assert LayoutView.test_nets(LayoutView.other_networks()) == [
+               %{
+                 title: "POA Sokol",
+                 url: "https://blockscout.com/poa/sokol",
+                 test_net?: true
+               },
+               %{
+                 title: "LUKSO L14 testnet",
+                 url: "https://blockscout.com/lukso/l14",
+                 test_net?: true,
+                 hide_in_dropdown?: true
+               }
+             ]
+    end
+  end
+
+  describe "dropdown_nets/0" do
+    test "get all dropdown networks list based on env variables" do
+      Application.put_env(:block_scout_web, :other_networks, @supported_chains_pattern)
+
+      assert LayoutView.dropdown_nets() == [
+               %{
+                 title: "POA Core",
+                 url: "https://blockscout.com/poa/core"
+               },
+               %{
+                 title: "RSK Mainnet",
+                 url: "https://blockscout.com/rsk/mainnet",
+                 other?: true
+               },
+               %{
+                 title: "POA Sokol",
+                 url: "https://blockscout.com/poa/sokol",
+                 test_net?: true
+               }
+             ]
+    end
+  end
+
+  describe "dropdown_head_main_nets/0" do
+    test "get dropdown all main networks except those of 'other' type list based on env variables" do
+      Application.put_env(:block_scout_web, :other_networks, @supported_chains_pattern)
+
+      assert LayoutView.dropdown_head_main_nets() == [
+               %{
+                 title: "POA Core",
+                 url: "https://blockscout.com/poa/core"
+               }
+             ]
+    end
+  end
+
+  describe "dropdown_other_nets/0" do
+    test "get dropdown networks of 'other' type list based on env variables" do
+      Application.put_env(:block_scout_web, :other_networks, @supported_chains_pattern)
+
+      assert LayoutView.dropdown_other_nets() == [
+               %{
+                 title: "RSK Mainnet",
+                 url: "https://blockscout.com/rsk/mainnet",
+                 other?: true
+               }
+             ]
+    end
+  end
 end