Tefillin over Watch

Question: Do I need to remove my watch before putting on my tefillin?

Answer: The Mishna (Megilla 24b) teaches that there must not be anything in between one’s tefillin and their arm (chatzitza). Thus, the Shulchan Aruch (OC 27:4) writes that one should ensure to place one’s tefillin directly on their head and arm. The Rema, based on the Rashba (1:827), qualifies this to the tefillin boxes, though allows one to have something under the retzuos (straps). The Taz (OC 27:4) and Magen Avraham (OC 27:5) challenge the Rema, as the Rashba concludes that one should ideally refrain from any chatzitza under one's retzuos.

The Mishna Berura (27:17) writes that this leniency only applies to the winding around the arm (kerichos). There must not be any chatzitza by the tying (keshira), however. R' Moshe Sternbuch (Teshuvos Vehanhagos 2:26) explains that the seven kerichos around the forearm are not essential to fulfil the mitzva, one would fulfil the mitzva even if one did not remove their watch.

R’ Ephraim Greenblatt (Rivevos Ephraim 4:16:7) writes that according to the Chasam Sofer (YD 192) one must remove one’s rings before wrapping tefillin. The windings round the fingers are considered keshira and so a ring would be a chatzitza.

R’ Ovadia Yosef (Yabia Omer OC 2:2; Yechave Daas 3:2) writes that especially if one wears one’s watch normally at the end of their arm after the seven wrappings, it does not act as a chatzitza. Nonetheless, he writes that while we should not prevent others from wearing their watch, it is ideal to remove it (See Emes Leyaakov OC 27:n31).

In conclusion, one should remove one’s ring before wrapping one’s tefillin round that finger. While one is yotze if they keep their watch on, it is commendable to remove it.