Syedna Haatim Zakiyuddin (Arabic: حاتم زکي الدین) (born 10 September 1959), is the 45th Saiyedna and Da'i al-Mutlaq of Alavi Bohras and Naa'ib (نائب) representative, vicar, legatee and deputy of the progeny of 21st Fatimid Isma'ili Imam Abul Qaasim at-Taiyeb during the time of his Concealment from Cairo in 528 AH/1132 AD which is called Daur us Satr (دور الستر).

During his stay in Mumbai, he did all things possible to enrich the library of Da'wah Shareefah by acquiring Isma'ili-Taiyebi MSS[5] and rare Islamic books.

He did tarbiyat and Taiyebi upbringing of Mumbai mumineen on the morals of Ahl ul Bayt (as) by fulfilling the responsibilities of Moharram and Shahrullaah.

He took very strong step and robust decision in 1423 AH/2011 AD by sending his eldest son Bhaisaheb Sa’eed ul-Khayr, who would be elevated to the status of Mazoon e Mutlaq,[6] to Qumm, Iran for graduation in Arabic Language and Literature.

The status of Ra's ul-Hudood[6] is headed by his youngest brother Dr. Zulqarnain Bhaisaheb Hakeemuddin who was assigned this responsibility along with Mukaasir al-Mutlaq.

When Saiyedna saheb did Nass-e-jali[8] and appointed-declared his eldest son as his successor 46th Da'i al-Mutlaq, Mukaasir al-Mutlaq was awarded a unique laqab as "Siqat ud-Da'wat il-Haadiyat il-'Alaviyah" (ثقۃ الدعوۃ الهادیۃ العلویۃ, SDHA) meaning the most trusted, and Ra's ul-Hudood was awarded a special laqab as "Naasir ud-Da'wat it-Taiyebiyah" (ناصر الدعوۃ الطیبیۃ, NDT) meaning one who assist in Da'wah affairs.

He played a pivotal role in revamping the syllabus of Madrasah Taiyebiyah by making the learning of Lisaan ud-da’wat compulsory for all pupils.

In 1420 AH/1999 AD, Saiyedna saheb with 44th Da’i, undertook long journey of 42 days for Ziyaaraat e Mubaarakah in Iraq, Jordan, Egypt, Israel, Syria and Yemen.

For every small or big spiritual or social occasion, printed literature is furnished by Saiyedna saheb's office giving appropriate instructions to the applicants.

Be it at Devdi Mubaarak – Residence of Saiyedna saheb, masjid, community hall, private majlis, graveyard for the occasions pertaining to inauguration, sehra, birthday, marriage, misaaq (divine oath), roza-iftaari, ziyaafat, khatnah or deceased person's sadaqallaah.

The concept of pre-wedding religious counselling and personal consultation was initiated some years back and now, one can find positive results out of it as the instances of marital discord and divorces has considerably decreased.

In the majlis known as Dhaaru-Fixing of the date of marriage and the day when wedding cards are distributed in the community, the to be-couple sits in front of Saiyedna saheb and he himself explains the realities of married life, its responsibilities and sacrifices.