| 22/06/23 | 10:38:41 | 22 Jun 2023 | | Costain Appointed Magnox Decommissioning Framework |
| 08/06/23 | 16:17:22 | 8 Jun 2023 | | Update Regarding A66 Project |
| 11/05/23 | 16:49:08 | 11 May 2023 | | Result of AGM |
| 11/05/23 | 07:00:04 | 11 May 2023 | | AGM Statement |
| 20/04/23 | 09:40:24 | 20 Apr 2023 | | External Appointment |
| 06/04/23 | 14:29:30 | 6 Apr 2023 | | Grant of Share Plan Awards |
| 06/04/23 | 11:51:46 | 6 Apr 2023 | | Holding(s) in Company |
| 04/04/23 | 10:33:43 | 4 Apr 2023 | | Notice of AGM and Annual Report and Accounts |
| 30/03/23 | 12:58:31 | 30 Mar 2023 | | Long Term Incentive Plan - Listing Application |
| 14/03/23 | 07:00:06 | 14 Mar 2023 | | Results For The Year Ended 31 December 2022 |
| 30/01/23 | 16:35:30 | 30 Jan 2023 | | Price Monitoring Extension |
| 03/01/23 | 13:09:29 | 3 Jan 2023 | | Block Listing Six Monthly Return |
| 21/12/22 | 12:47:14 | 21 Dec 2022 | | Director/PDMR Shareholding |
| 29/11/22 | 07:00:01 | 29 Nov 2022 | | Costain Partners with Heathrow Airport |
| 21/11/22 | 07:00:10 | 21 Nov 2022 | | Extension of Bank Debt and Bonding Facilities |
| 01/11/22 | 16:42:24 | 1 Nov 2022 | | Director/PDMR Shareholding |
| 30/09/22 | 14:32:25 | 30 Sept 2022 | | A303 Delivery Assurance Partnership |
| 27/09/22 | 07:00:12 | 27 Sept 2022 | | Directorate Change |
| 24/08/22 | 07:00:04 | 24 Aug 2022 | | Strong operational resilience and cash performance |
| 20/07/22 | 07:00:08 | 20 Jul 2022 | | Trading in line with strong cash performance |
| 01/07/22 | 16:40:48 | 1 Jul 2022 | | Second Price Monitoring Extn |
| 01/07/22 | 16:35:47 | 1 Jul 2022 | | Price Monitoring Extension |
| 01/07/22 | 09:00:04 | 1 Jul 2022 | | Block listing Interim Review |
| 16/06/22 | 14:17:05 | 16 Jun 2022 | | TR-1: Notification of Major holdings |
| 01/06/22 | 11:10:38 | 1 Jun 2022 | | Total Voting Rights |
| 05/05/22 | 16:47:48 | 5 May 2022 | | Result of AGM |
| 05/05/22 | 07:00:03 | 5 May 2022 | | Trading in line with market expectations |
| 04/05/22 | 08:55:39 | 4 May 2022 | | LONG TERM INCENTIVE PLAN – LISTING APPLICATION |
| 06/04/22 | 17:24:41 | 6 Apr 2022 | | Grant of Share Plan Awards |
| 30/03/22 | 10:30:02 | 30 Mar 2022 | | Notice of AGM and Annual Report and Accounts |
| 28/03/22 | 07:00:09 | 28 Mar 2022 | | Directorate Change |
| 25/03/22 | 16:35:19 | 25 Mar 2022 | | Price Monitoring Extension |
| 10/03/22 | 16:36:35 | 10 Mar 2022 | | Price Monitoring Extension |
| 09/03/22 | 07:00:12 | 9 Mar 2022 | | Directorate Change |
| 09/03/22 | 07:00:10 | 9 Mar 2022 | | Strong performance in 2021 |
| 24/02/22 | 07:00:07 | 24 Feb 2022 | | Peterborough & Huntingdon contract resolution |
| 12/01/22 | 07:00:04 | 12 Jan 2022 | | Directorate Change |
| 04/01/22 | 10:00:08 | 4 Jan 2022 | | Block Listing Six Monthly Return |
| 13/12/21 | 07:00:08 | 13 Dec 2021 | | Update on P&H contract and current trading |
| 10/11/21 | 10:49:37 | 10 Nov 2021 | | Director/PDMR Shareholding |
| 02/11/21 | 13:33:19 | 2 Nov 2021 | | Director/PDMR Shareholding |
| 28/09/21 | 07:00:05 | 28 Sept 2021 | | Appointment of non-executive director |
| 17/09/21 | 16:36:39 | 17 Sept 2021 | | Price Monitoring Extension |
| 25/08/21 | 07:00:02 | 25 Aug 2021 | | Interim Results |
