Exhibit 99.1

Dr. Reddy’s Laboratories Ltd. 8-2-337, Road No. 3, Banjara Hills Hyderabad – 500 034, Telangana, India   CIN: L85195TG1984PLC004507   Tel: + 91 40 4900 2900 Fax: + 91 40 4900 2999 Email: mail@drreddys.com Web: www.drreddys.com

July 22, 2026

National Stock Exchange of India Ltd. (Scrip Code: DRREDDY)

BSE Limited. (Scrip Code: 500124)

New York Stock Exchange Inc. (Stock Code: RDY)

NSE IFSC Ltd. (Stock Code: DRREDDY)

Dear Sir/Madam,

Sub: Outcome of Board Meeting held on July 22, 2026

Pursuant to Regulations 30 and 33 and other applicable provisions of Securities and Exchange Board of India (Listing Obligations and Disclosure Requirements) Regulations, 2015 (“SEBI Listing Regulations”) and in furtherance to our letter dated June 22, 2026, we would like to inform that the Board of Directors of the Company, at their meeting held today, i.e. July 22, 2026, have inter alia considered and approved the following:

Pursuant to the recommendation of the Nomination, Governance and Compensation Committee, the Board of Directors of the Company, at their meeting held today, approved the appointment of Dr. Sridevi Khambhampaty as Global Head of Biologics and Senior Management Personnel of the Company, and her induction as a Member of the Management Council, effective July 22, 2026.

The updated list of the Company’s Senior Management Personnel, reflecting the above appointment, is enclosed as Annexure A1.

This is in continuation of our letter dated May 12, 2026, wherein the Company had informed that it has appointed M/s Deloitte Haskins & Sells, LLP, (Firm Registration No. 117366W/W-100018), as the Statutory Auditors of the Company, in terms of the provisions of Companies Act, 2013, for a term of five consecutive years, commencing from the conclusion of the 42nd AGM till the conclusion of the 47th AGM, subject to the approval of the shareholders at the ensuing AGM.

We further wish to inform that to align with the above and basis the recommendation of the Audit Committee, the Board of Directors have approved the appointment of M/s Deloitte Haskins & Sells, LLP, as the Independent Registered Public Accounting Firm of the Company for the purpose of auditing the financial statements of the Company to be included in the Company’s Annual Report on Form 20-F and reviewing the interim financial statements to be filed with the U.S. Securities and Exchange Commission on Form 6-K.

The disclosure required under Regulation 30 of the SEBI Listing Regulations read with SEBI Master Circular No. HO/49/14/14(7)2025-CFD-POD2/I/3762/2026 dated January 30, 2026, is enclosed as Annexure A and B.

The Board Meeting commenced at 2:30 p.m. IST and concluded at 4:03 p.m. IST.

This is for your information and records.

Thanking you.

Yours faithfully,

For Dr. Reddy’s Laboratories Limited

K Randhir Singh

Company Secretary, Compliance Officer & Head-CSR

Encl: as above

Annexure A

Details of Dr. Sridevi Khambhampaty

Brief Profile of Dr. Sridevi Khambhampaty

Dr. Sridevi is an accomplished biopharmaceutical leader with over two decades of experience spanning Biologics R&D, Quality, and Business leadership. Most recently, she served as the CEO of Shilpa Biologics, where she led the organization’s growth and strategic direction. Prior to this, she held senior leadership roles at Syngene International and Intas Biopharma.

In her previous stint at Dr Reddy’s, Dr. Sridevi led teams in Product Development and Quality Control at Biologics and contributed to several of our current products in biosimilars. She brings deep expertise in biologics, development strategy, regulatory sciences, and cross-functional leadership, along with extensive experience in building and scaling high-performing teams. She holds a PhD in Biological Sciences from NCBS (TIFR) and completed her postdoctoral research at Stanford University School of Medicine.

Annexure A1

List of revised Senior Management Personnel

Annexure B

Details of M/s Deloitte Haskins & Sells, LLP, Chartered Accountants as Independent Registered Public Accounting Firm